We provide structure of atom practice exercises, instructions, and a learning material that allows learners to study outside of the classroom. We focus on structure of atom skills mastery so, below you will get all questions that are also asking in the competition exam beside that classroom.
List of structure of atom Questions
| Question No | Questions | Class |
|---|---|---|
| 1 | With increase in distance from the nucleus, energy of electron. increases though velocity of electron decreases. How do you account for this? |
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| 2 | Total number of orbitals present in the given stationary state for the principal quantum number having value of ( n=3 ) ? A . 9 B. 7 ( c cdot 4 ) D. 6 |
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| 3 | Which element with lowest atomic number ( mathbf{A} cdot_{19} K ) В ( cdot_{24} C r ) ( mathbf{c} cdot_{11} N a ) D・ ( _{29} C u ) |
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| 4 | The difference between the angular momentum of two orbits of ( H e^{+2} ) is ( frac{2 h}{pi} ) The energy of an electron present in the higher orbit is -1.51 eV. Indentify the lower orbit. A B. 2 ( c cdot 3 ) D. 4 |
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| 5 | Radius of nucleus may be given as ( boldsymbol{R}_{N}=boldsymbol{R}_{0} boldsymbol{A}^{1 / 3}, ) where ( boldsymbol{A}= ) mass number and ( R_{0}= ) constant. Calculate the density of nucleus of an atom if ( boldsymbol{R}_{0}=mathbf{1 . 2} times mathbf{1 0}^{-mathbf{1 5}} ) |
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| 6 | What are the possible of ( m_{5} ) when ( m_{1} ) have ( +1,+2,+3 ? ) |
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| 7 | Non-directional orbital is: ( mathbf{A} cdot 3 s ) B . ( 4 f ) c. ( 4 d ) D. ( 4 p ) |
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| 8 | Though there is only one electron in a hydrogen atom, the spectrum of hydrogen contains a number of lines. How do you explain this? | 11 |
| 9 | According to Bohr’s theory of hydrogen atom it can be concluded that the radius of stable orbits is proportional to ( mathbf{A} cdot n^{2} ) B. ( frac{1}{n} ) ( c ) D. ( frac{1}{n^{2}} ) |
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| 10 | In isotones the atomic number and mass numbers are: A. same B. different c. equal D. zero |
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| 11 | Calculate the accelerating potential that must be imparted to a proton beam to wavelength of ( 0.005 mathrm{nm} ) | 11 |
| 12 | The nuclei of which one of the following pairs of nuclei are isotones: ( A cdot_{34} mathrm{Se}^{74},_{31} mathrm{Ga}^{71} ) B ( cdot_{38} mathrm{Sr}^{84},_{38} mathrm{Sr}^{86} ) C ( cdot_{42} mathrm{Mo}^{92},_{40} mathrm{Zr}^{9} ) D. ( _{20} mathrm{Ca}_{2}^{40},_{16} mathrm{S}^{32} ) |
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| 13 | What the significance of negative electronic energy? | 11 |
| 14 | 47. X-rays are produced by accelerating electrons by voltage V and let they strike a metal of atomic number Z. The highest frequency of X-rays produced is proportional to (a) V (b) Z (c) (Z-1) (d) (Z-1) oto 11 |
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| 15 | When electron jumps from ( mathrm{N} ) shell to shell, the energy is: A. emitted B. absorbed c. reflected D. cannot be predicted |
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| 16 | The uncertainties in the velocities of two particles, ( A ) and ( B ) are 0.05 and ( 0.02 m s^{-1} ) respectively. The mass of ( B ) is five times to that of the mass of ( boldsymbol{A} ) What is the ratio of uncertainties ( frac{Delta x_{A}}{Delta x_{B}} ) in their positions? A . 2 B. 0.25 ( c cdot 4 ) ( D ) |
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| 17 | The mass number is the sum of the number of protons and the number of neutrons in an atom. State whether the given statement is |
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| 18 | Heisenberg Uncertainity principle is not valid for: A. moving electron B. motor car c. stationary particles D. both B and C |
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| 19 | The first use of quantum theory to explain the structure of atom was made by: A. Heisenbergg B. Bohr c. Planck D. Einstein |
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| 20 | Q5. How many electrons in an atom can have n + 1 = 6? | 11 |
| 21 | What is the electron configuration of ( boldsymbol{V}^{2+} ? ) ( mathbf{A} cdot[A r] 4 s^{2} 3 d^{3} ) B . ( [A r] 4 s^{1} 3 d^{4} ) ( mathbf{c} cdot[A r] 3 d^{3} ) D ( cdot[A r] 4 s^{2} 3 d^{1} ) |
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| 22 | Maximum frequency of emission is obtained for the transition: ( mathbf{A} cdot n=2 ) to ( n=1 ) B. ( n=6 ) to ( n=2 ) c. ( n=1 ) to ( n=2 ) D. ( n=2 ) to ( n=6 ) 6 |
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| 23 | Oxygen atom has an atomic mass of 16 u and eight neutrons in its nucleus. What is its atomic number? ( A cdot 4 ) B. 12 ( c cdot 8 ) D. 6 |
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| 24 | State True or False. ( mathrm{p}_{z} ) orbital is symmetrical about y-axis : A. True B. False |
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| 25 | The minimum energy required to overcome the attractive forces between an electron and the surface of Ag metal is ( 5.52 times 10^{-19} mathrm{J} ). What will be the maximum kinetic energy of electron ejected out from Ag which is being exposed to UV-light of ( =360 mathrm{A} ? ) |
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| 26 | Which of the following is the wrong statement? A. ( O N F ) and ( O N O^{circ} ) are isoelectronic B. ( C_{2} ) molecules is expected to exhibit diamagnetic behavior if ( s-p ) mixing is not operative c. Ozone is diamagnetic gas |
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| 27 | If the kinetic energy of a particles is reduced to half, de broglie wave length becomes: A. 2 times B. ( frac{1}{sqrt{2}} ) times c. 4 times D. ( sqrt{2} ) times |
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| 28 | A neutral atom of fluorine has a mass number of 19 and an atomic number of 9. How many neutrons does it have? A . 10 B. 9 c. 19 D . 28 E. It is impossible to determine from the information given |
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| 29 | 77. An electron and a photon have same wavelength. If pic the momentum of electron and E the energy of photon the magnitude of plE in SI unit is (a) 3.0 x 108 (b) 3.33 x 10-9 (c) 9.1 x 10-31 (d) 6.64 x 10-34 |
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| 30 | Let a light of wavelength ( lambda ) and intensity ( boldsymbol{I}^{prime} ) strikes a metal surface to emit ( boldsymbol{x} ) electrons per second. Average energy of each electron is ‘ ( y^{prime} ) unit. What will happen to ‘ ( x ) ‘ and ‘ ( y ) ‘ when (a) ( lambda ) is halved (b) intensity ( I ) is doubled? |
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| 31 | Assertion Atomic number is a more fundamental property of an element than its atomic mass. Reason Atomic number is equal to number of protons in an atom. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 32 | Thomson’s atomic model is also called: A. water melon model B. christmas pudding model ( c . ) both a and ( b ) D. none of above |
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| 33 | When alpha particles are used to bombard gold foil, most of the alpha particles pass through undeflected. This result indicates that most of the volume of a gold atom consists of: A. deuterons B. neutrons c. protons D. unoccupied space |
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| 34 | Which particle among the following will have the smallest de Broglie wavelength, assuming that they have the same velocity? A. Positron B. Photon c. ( alpha ) – particle D. Neutron |
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| 35 | Calculate the orbital angular momentum of the following orbitals: (a) ( 3 p ) (b) ( 3 d ) (c) ( 3 s ) |
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| 36 | The Bohr’s radius for the fifth orbit of the hydrogen atom will be: A . 0.529 A B. 2.645 A C. ( 13.225 mathrm{A} ) D. none of above |
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| 37 | “The exact path of an electron in ( 2 p ) orbital cannot be determined”, This statement is based upon: A. Hund’s rule B. Bohr’s’s rule c. Uncertainty principle D. Aufbau principal |
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| 38 | ( _{6}^{14} boldsymbol{C} rightarrow_{7}^{14} boldsymbol{N}+boldsymbol{X} ) The above nuclear reaction is an example of : A. ( alpha ) decay B ( cdot beta^{-} ) decay ( mathbf{c} cdot beta^{+} ) decay D. Fusion E . ( gamma ) decay |
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| 39 | How many Balmer spectral lines will be obtained when the excited electrons return from 8th shell to 2nd shell? A . 21 B. 4 c. 10 D. 15 |
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| 40 | The species which are isoelectronic with CO is: A ( cdot C l ) в. ( O H^{-} ) ( mathrm{c} cdot mathrm{CH}_{3}^{+} ) D. ( N_{2} ) |
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| 41 | Angular momentum in an orbit is ( 3 n ) The value of ( n ) is : ( mathbf{A} cdot mathbf{1} ) B. 2 ( c cdot 3 ) D. 4 |
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| 42 | Total number of orbitals associated with third shell will be A .2 B. 4 ( c cdot 9 ) D. |
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| 43 | An electron in hydrogen atom is excited to ‘N’ shell. What are the possible transitions it can undergo ? Compare the energies of transitions. |
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| 44 | What will happen when an electron jumps from an excited energy state to a more stable energy state in a hydrogen atom? A. Electromagnetic radiation is emitted by the atom B. Electromagnetic radiation is absorbed by the atom C. The atom becomes a positively charged ion D. The atom becomes a negatively charged ion E. The atom undergoes nuclear decay |
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| 45 | Which of the following is not a characteristic of XX-rays? A. The radiation can ionize gas B. It causes ( Z n S ) to fluorescence C. Deflected by electric and magnetic fields D. Have wavelength shorter then ultraviolet rays |
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| 46 | The value of atomic number(z) is: | 11 |
| 47 | Calculate the number of neutrons in the remaining atom after emission of an alpha particle from ( _{92}^{238} U ) atom. |
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| 48 | Which energy state of a doubly ionized lithium ( left(L i^{++}right) ) has the same energy as that of the ground state of hydrogen ( z=3, ) for lithium): ( mathbf{A} cdot n=1 ) B. ( n=2 ) ( mathbf{c} cdot n=3 ) D. ( n=4 ) |
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| 49 | Which of the following are isotones? This question has multiple correct options A. ( A r_{18}^{40} ) B. ( C a_{a_{0}^{2}}^{2} ) c. ( S c_{c 13}^{43} ) D. ( S c_{21}^{41} ) |
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| 50 | If ( n=6, ) the correct sequence for filling of electrons will be: A ( cdot n s rightarrow n p rightarrow(n-1) d rightarrow(n-2) f ) B . ( n s rightarrow(n-2) f rightarrow(n-1) d rightarrow n p ) C ( cdot n s rightarrow(n-1) d rightarrow(n-2) f rightarrow n p ) D. ( n s rightarrow(n-2) f rightarrow n p rightarrow(n-1) d ) |
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| 51 | Which of the two orbitals have lower energy among ( 4 s ) and ( 3 d ? ) |
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| 52 | Show that the Balmer series occurs between ( 3647 dot{A} ) and ( 6563 hat{A} ) ( left(boldsymbol{R}=mathbf{1} . mathbf{0} mathbf{9} mathbf{6} mathbf{8} times mathbf{1} mathbf{0}^{mathbf{7}} boldsymbol{m}^{-mathbf{1}}right) ) |
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| 53 | ( 0.25 g ) of an element ( M ) reacts with excess fluorine to produce ( 0.547 g ) of the hexafluoride ( M F_{6} . ) What is the element? A ( . C r ) в. ( M o ) ( c cdot s ) D. ( T e ) |
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| 54 | The velocity of an electron in a certain Bohr orbit of H-atom bears the ratio 1: 275 to the velocity of light. The quantum number (n) of the orbit is : ( A cdot 3 ) B. 2 ( c ) ( D cdot 4 ) |
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| 55 | Electromagnetic radiation of wavelength ( 242 mathrm{nm} ) is just sufficient to ionise the sodium atom. Calculate the ionisation energy of sodium atom? ( (c= ) ( 3 times 10^{8} mathrm{ms}^{-1}, mathrm{h}=6.626 times 10^{-34} mathrm{Js} ) A ( cdot 5.6 times 10^{-19} k J ) В . ( 6.9 times 10^{-18} k J ) c. ( 8.2 times 10^{-19} mathrm{J} ) D. 495 kJ |
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| 56 | Which element with lowest atomic number follows rule (b)? ( A cdot 19^{k} ) B. 24 ( ^{c} ) ( c cdot 11^{N a} ) D. ( 29^{c} ) |
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| 57 | ( boldsymbol{E}_{boldsymbol{n}}=-frac{mathbf{3 1 3 . 6}}{boldsymbol{n}^{2}}, ) if the value of ( boldsymbol{E}_{boldsymbol{i}}= ) -34.84 to which value ‘ ( n ) ‘ corresponds: A . 2 B. 4 c. 1 D. 3 |
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| 58 | have 4 to 8 electrons in the outermost shell. A. Non-metals B. Metalss c. Metalloids D. Transition elements |
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| 59 | Multiple photoelectric effect experiments were conducted by applying a variety of visible wavelengths to a metal surface and recording the electrical current produced. Data from these experiments provided evidence for which of the following claims? A. Electromagnetic radiation exhibit wave-like characteristics. B. Electromagnetic radiation exhibit particle-like characteristics. C. Electrons have quantized energies in an atom. D. Electrons behave like waves in an atom. |
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| 60 | Chemically, matter can be classified as A. pure and impure substances B. elements, compounds and mixtures c. solids, liquids and gases D. metals and non-metals |
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| 61 | Assertion ( beta ) -particles are deflected more than ( alpha ) particles in a given electric field. Reason Charge on ( alpha ) -particles is larger than on ( beta ) -particles. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but the Reason is correct |
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| 62 | Suppose an electron is attracted towards the origin by a force ( frac{mathbf{k}}{mathbf{r}} ) where ( mathbf{k}^{prime} ) is a constant and ( mathbf{r}^{prime} ) is the distance of the electron from the origin. By applying Bohr model to this system, the radius of the ( n^{text {th }} ) orbital of the electron is found to be ( mathbf{r}_{mathbf{n}}^{text {‘ and the kinetic energy of the }} ) electron to be’ ( mathbf{T}_{mathbf{n}} . ) Then which of the following is true? A ( cdot mathrm{T}_{mathrm{n}} propto frac{1}{mathrm{n}}, mathrm{r}_{mathrm{n}} propto mathrm{n} ) B. ( mathrm{T}_{mathrm{n}} propto frac{1}{mathrm{n}}, mathrm{r}_{mathrm{n}} propto mathrm{n}^{2} ) ( c cdot mathrm{T}_{mathrm{n}} propto frac{1}{mathrm{n}^{2}}, mathrm{r}_{mathrm{n}} propto mathrm{n}^{2} ) D. ( T_{n} ) independent of ( n, r_{n} propto n ) |
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| 63 | What is the maximum number of emission lines obtained when the excited electron of a H atom in ( n=5 ) drops to the ground state? A ( cdot 12 ) B. 15 ( c cdot 2 ) D. 10 |
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| 64 | Which of the following have identical value of e/m? A. A proton & a neutron B. A proton & a deuterium c. Deutorium & an ( alpha ) -particle D. An electron and ( gamma ) -rays |
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| 65 | Calculate no. of ions, atoms, protons, electrons in ( 3 g C O_{3}^{2-} ) |
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| 66 | ( begin{array}{lll}text { Element } & text { Reaction with water } & triangle boldsymbol{T}left(^{circ} boldsymbol{C}right) \ mathrm{A} & text { small bubbles formed } & -2 \ mathrm{B} & text { vigorous bubbling } & +10 \ mathrm{C} & text { dissolves, no bubbles } & 0 \ mathrm{D} & text { small bubbles formed } & 0end{array} ) Which electron configuration would match the laboratory data for Element ( mathrm{B} ? ) ( mathbf{A} cdot[N e] 3 s^{2} ) ( mathbf{B} cdot[X e] 6 s^{2} ) ( mathbf{C} cdot[A r] 4 s^{2} 3 d^{10} ) D. ( [N e] 3 s^{2} 3 p^{3} ) |
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| 67 | The electron is present in the N shell in H-atom. When energy is lost, spectral line may be observed in ( ldots ldots . . ) region. ( A ). infra-red B. visible c. ultra-violet D. any of these |
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| 68 | Statement I: ( _{6}^{14} C ) and ( _{6}^{12} C ) are isomers of the element carbon.
Statement II: Isomers contain the same |
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| 69 | The ionising power of ( alpha, beta ) and ( gamma ) -rays is in the decreasing order: A ( . alpha>beta>gamma ) в. ( beta>alpha>gamma ) c. ( gamma>alpha>beta ) D. ( beta>gamma>alpha ) |
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| 70 | Splitting of spectral lines in electric field is called stark effect. A. True B. False |
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| 71 | A potential difference of ( 20 mathrm{KV} ) is applied across an X-ray tube. Find the minimum wavelength of X-ray generated. | 11 |
| 72 | A mono-electronic species in energy level with energy X was provided with excess of energy so that it jumps to higher energy level with energy Y. If it can emit 6 wavelengths originated from all possible transition between these groups levels, then which of the following relation is correct? (Here ( n ) is the principle quantum of energy level ( X ) ) A ( . X / Y=(n-1)^{2} ) B. ( X / Y=1+3 / N ) c. ( sqrt{(X / Y)}=1+3 / N ) D. ( X / Y=N / 6 ) |
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| 73 | Q4. What is the difference between the notations I and L? | 11 |
| 74 | J J Thomson Model could not able to explain the following? A. Stability of Atom B. electrical neutrality of atom c. stability of nuclcus D. all of these |
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| 75 | Assertion Energy of electron in 1st orbit of ( boldsymbol{H} boldsymbol{e}^{+} ) is more than that in Hydrogen atom. Reason Nuclear charge is more in ( H e^{+} ) than in Hydrogen. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 76 | By changing the metal electrodes and gas inside the cathode ray tube, A. The same particles-electrons were produced. B. The same particles-neutrons were produced. c. The same particles-protons were produced D. New particles were produced |
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| 77 | Plum Pudding Model of the Atom was given by: A. Thomson B. Rutherford c. Bohr D. chadwick |
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| 78 | The uncertainty in position of an electron ( left(boldsymbol{m}=mathbf{9 . 1} times mathbf{1 0}^{-mathbf{2 8}} mathbf{g m}right) ) moving with a velocity ( 3 times 10^{4} mathrm{cm} / mathrm{s} ) accurate upto ( 0.001 % ) will be: ( A . quad 3.84 mathrm{cm} ) B. 1.92 ( mathrm{cm} ) c. ( 7.68 mathrm{cm} ) D. 5.76 cm |
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| 79 | The work function of a metal is 4 eV. If light of frequency ( 2.3 times 10^{15} mathrm{Hz} ) is incident on metal surface, then: A. no photoelectron will be ejected B. 2 photoelectron of zero kinetic energy are ejected C. 1 photoelectron of zero kinetic energy is ejected it D. 1 photoelectron is ejected, which required the stopping potential of 5.52 volt |
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| 80 | Which atom would require the shortest wavelength photon to remove a single electron? A. ( M g ) B. ( S ) i ( c . P ) D. E . ( C l ) |
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| 81 | The quantum number n of the state finally populated in ( mathbf{H e}^{+} ) ions is: ( A cdot 2 ) B. 3 ( c cdot 4 ) D. 5 |
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| 82 | The correct set of quantum numbers for ( t ) he last electron of ( N a^{+} ) is : ( mathbf{A} cdot 3,0,0,-frac{1}{2} ) B. ( 3,1,0,+frac{1}{2} ) ( mathbf{c} cdot 3,1,1,+frac{1}{2} ) D. ( 2,1,0,-frac{1}{2} ) |
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| 83 | Which of the following sets of ions represents a collection of isoelectronic species? A ( cdot N^{3}, O^{3}, F^{-}, S^{2-} ) B . ( L i^{+}, N a^{+}, M g^{2+}, C a^{2+} ) C ( cdot K^{+}, C l^{-}, C a^{2+}, S c^{3+} ) D. ( B a^{2+}, S r^{2+}, K^{+}, C a^{2+} ) |
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| 84 | Determine uncertainty in the position of an electron moving with a velocity 300 ( mathrm{m} cdot mathrm{sec}^{-1} ) accurate up to ( 0.001 % ) ( left[h=6.63 times 10^{-34} mathrm{J} . mathrm{s} ) and mass of right. electron ( =9.1 times 10^{-31} mathrm{kg} ) A ( cdot 1.92 times 10^{-2} mathrm{m} ) в. ( 1.5 times 10^{-2} mathrm{m} ) C. ( 2.5 times 10^{-2} m ) D. ( 2.5 times 10^{-3} mathrm{m} ) |
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| 85 | If there are three possible values ( (-1 / 2,0,+1 / 2) ) for the spin quantum, then electronic configuration of ( boldsymbol{K}(mathbf{1 9}) ) will be: A ( cdot 1 s^{3}, 2 s^{3} 2 p^{9}, 3 s^{3} 3 p^{text {th }} ) B . ( 1 s^{2}, 2 s^{2} 2 p^{6}, 3 s^{2} 3 p^{6}, 4 s^{1} ) C ( cdot 1 s^{2}, 2 s^{2} 2 p^{9}, 3 s^{2} 3 p^{4} ) D. None of these |
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| 86 | Who is the discoverer of Proton? A. J. J. Thomson B. James Chadwick c. Ernest Rutherford D. None of the above |
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| 87 | State whether the given statement is true or false: Elements with an odd number of protons usually have only one or two stable isotopes. A. True B. False |
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| 88 | Deduce the condition when the De- Broglie wavelength associated with an electron would be equal to that associated with a proton if a proton is 1836 times heavier than an electron |
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| 89 | Which of the following values corresponds to the value of energy required to remove the second electron from the ground state of helium atom? ( mathbf{A} cdot-27.2 e V ) B. ( -13.6 e V ) c. ( -6.8 e V ) D. ( -54.4 e V ) |
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| 90 | The maximum kinetic energy of photoelectrons ejected from a metal, when it is irradiated with radiation of frequency ( 2 times 10^{14} s^{-1} ) is ( 6.63 times 10^{-20} J ) Find the threshold frequency of the metal. |
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| 91 | The work function for caesium atom is 1.9 eV. Calculate (a) threshold wavelength and (b) threshold frequency of the radiation. If caesium is irradiated with a wavelength of 500 nm. Calculate the kinetic energy and the velocity of the ejected electron. |
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| 92 | An electron beam can undergo diffraction by crystals. Through what potential should a beam of electrons be accelerated so that its wavelength becomes equal to 1.54 A? A. 13.6 volt B . 1.54 volt c. 1 volt D. 63.44 volt |
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| 93 | The increase order for the value of ( e / m ) (charge to mass ratio) for electron ( (e) ) proton ( (p) ; ) neutron ( (n) ) and alpha particle ( (alpha) ) is: A ( cdot e<p<n<alpha ) в. ( n<p<e<alpha ) c. ( n<p<alpha<e ) D. ( n<alpha<p<e ) |
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| 94 | Choose the correct statement for proton. ( mathbf{A} cdot ) It is a nucleus of deuterium B. It is an ionized hydrogen atom C. It is an ionized hydrogen molecule D. It is an ( alpha ) – particle |
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| 95 | If the momentum of a particle which has a de Broglie wave length of 10 nm is ( A times 10^{-26} mathrm{ms}^{-1} ) then nearest integer value of ( A ) is : |
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| 96 | The line spectra of two elements are different because: A. the elements do not have the same number of neutrons B. they have different mass numbers C. their outermost electrons are at different energy levels D. all of the above |
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| 97 | In Thomson’s model of the atom, which of the following statements are correct? (i) The mass of the atom is assumed to be uniformly distributed over the atom. (ii) The positive charge is assumed to be uniformly distributed over the atom. (iii) The electrons are uniformly distributed in the positively charged sphere (iv) The electrons attract each other to stabilize the atom. A. (i), (ii) and (iii) B. (i) and (iii) c. (i) and (iv) D. (i), (iii) and (iv) |
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| 98 | Thomson atomic theory proved that the stream in cathode ray tube is made up of small particles which is piece of the atom and is : A. neutral B. negatively chargedd c. positively charged D. both A and B |
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| 99 | Radial probability distribution curve is shown for ( s ) -orbital. The curve is: A . ( 1 s ) B . ( 2 s ) ( c .3 s ) D. ( 4 s ) |
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| 100 | The mass of an atom of carbon is: A. ( 1 g ) В. ( 1.99 times 10^{-23} g ) c. ( 1 / 12 g ) D. ( 1.99 times 10^{23} g ) |
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| 101 | Which of the following are isobars? A ( . ) Ce, ( mathrm{Se} ) B. Fe, Se ( mathrm{c} cdot mathrm{Fe}, mathrm{Ce} ) D. Ce, Ni |
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| 102 | Minimum photocurrent which must be passed through the circuit A . 2.88 B. 1.44 ( c cdot 2.08 ) D. 0.64 |
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| 103 | In classical theory, i.e, in Rutherford atomic model path of the electron will be A. Circular B. Straight c. Parabolic D. Spiral |
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| 104 | Which one of the following does not contains electrons in ( 4 s ) subshells? Given that : Atomic numbers: ( boldsymbol{T} boldsymbol{i}= ) ( mathbf{2 2}, boldsymbol{V}=mathbf{2 3}, boldsymbol{C r}=mathbf{2 4}, boldsymbol{M} boldsymbol{n}=mathbf{2 5} ) A ( cdot T i ) B. ( V^{text {t }} ) ( c cdot C r^{+} ) D. ( M n^{+} ) |
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| 105 | What is the difference in number of neutrons in Protium and Deuterium? ( mathbf{A} cdot mathbf{1} ) B. 2 ( c cdot 3 ) ( D ) |
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| 106 | Which of the following conditions is incorrect for a well behaved wave function ( (mathbf{Psi}) ? ) A. ( Psi ) must be finite B. Psi must be single valued c. ( Psi ) must be infinite D. ( Psi ) must be continuous |
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| 107 | If K.E. of an electron, ( alpha ) -particle and a proton are represented by ( boldsymbol{E}_{1}, boldsymbol{E}_{2} ) and ( boldsymbol{E}_{3} ) respectively, (provided all these have same de Broglie wavelength) then: A. ( E_{1}=E_{2}=E_{3} ) B . ( E_{1}>E_{2}>E_{3} ) c. ( E_{1}>E_{3}>E_{2} ) D. ( E_{2}>E_{3}>E_{1} ) |
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| 108 | Assertion Bohr had to postulate that the electrons in stationary orbits around the nucleus do not radiate. Reason According to classical physics all moving electrons radiate. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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| 109 | Orbit is a region of space around the nucleus where the probability of finding an electron is maximum. A. True B. False |
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| 110 | An element belonging to 3d series of modern periodic table has spin magnetic moment =5.92 B.M.in +3 oxidation state. Determine the atomic number of element. |
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| 111 | 25. The work function of a metal is Wand 2 is the wavelength of the incident radiation. There is no emission of photoelectrons when (a) 2 > hc/W (b) 2 = hc/W (c) i< hc/W (d) 2 shc/W 2011 |
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| 112 | The frequency of radiation emitted when the electron falls from ( n=4 ) to ( boldsymbol{n}=mathbf{1} ) in a hydrogen atom will be (Given ionisation energy of ( boldsymbol{H}=mathbf{2 . 1 8} times ) ( 10^{-18} J a t o m^{-1} ) and ( h=6.626 times ) ( left.10^{-34} J-sright) ) ( mathbf{A} cdot 1.54 times 10^{15} s^{-1} ) В. ( 1.03 times 10^{15} s^{-1} ) C ( .3 .08 times 10^{15} s^{-1} ) D. ( 2 times 10^{15} s^{-1} ) |
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| 113 | Rutherford’s atomic model does not say anything about the arrangements of electron in an atom A. True B. False |
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| 114 | The velocity of an electron in the first Bohr orbit of a hydrogen atom is: A . ( 3.08 times 10^{6} mathrm{m} / mathrm{s} ) B. ( 2.18 times 10^{6} mathrm{m} / mathrm{s} ) ( mathbf{c} cdot 2.78 times 10^{6} m / s ) D. none of these |
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| 115 | Which one of the following has the greatest mass? A. Alpha particle B. Beta particle c. Neutron D. Gamma ray E . Positron |
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| 116 | The ground state energy of hydrogen atom is ( -13.6 mathrm{eV} . ) The energy of second excited state ( H e^{+} ) ion in eV is: A . -6.04 B . -27.2 c. -54.4 D. – 3. |
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| 117 | Which of the following statements are correct? This question has multiple correct options A. Electron density in ( X Y ) plane of ( 3 d_{x^{2}-y^{2}} ) orbital is zero. B. Electron density in ( X Y ) plane of ( 3 d_{z^{2}} ) orbital is zero. C. ( 2 s ) orbital has only one spherical node. D. For ( 2 p_{z} ) orbital ( Y Z ) is the nodal plane. |
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| 118 | Multiple Answer Question According to Bohr, when electronjumps from one shell to another: This question has multiple correct options A. if it gains energy, it moves away from the nucleus B. when it gains energy it moves towards the nucleus C. it emits energy in the form of radiations when it moves from higher energy level to lower energy level D. it always gains energy in the form of light |
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| 119 | The dual nature of radiation was proposed by : A. De Broglie B. Heisenberg c. JJ Thomson D. Einstein |
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| 120 | Infrared lamps are used in restaurants to keep the food warm. The infrared radiation is strongly absorbed by water, raising its temperature and that of the food. If the wavelength of infrared radiation is assumed to be ( 1500 n m ) then the number of photons per second of infrared radiation produced by an infrared lamp, that consumes energy at the rate of ( 100 W ) and is ( 12 % ) efficient only, is ( left(x times 10^{19}right) . ) The value of ( x ) is: ( left[text { Given: } boldsymbol{h}=mathbf{6 . 6 2 5} times mathbf{1 0}^{-mathbf{3 4}} boldsymbol{J}-boldsymbol{s}right] ) |
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| 121 | 20. If elements with principal quantum number n > 4 not allowed in nature, the number of possible elem de elements would have been (a) 32 (b) 60 (c) 64 (d) 4 |
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| 122 | Which of the following configuration represents a noble gas? ( mathbf{A} cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{10} 4 s^{2} 4 p^{6} 4 d^{10} 5 s^{2} ) B ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{10} 4 s^{2} 4 f^{14} 5 s^{2} ) ( mathbf{c} cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{10} 4 s^{2} 4 p^{6} 4 d^{10} 5 s^{2} 5 p^{6} ) D ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{10} 4 s^{2} 4 p^{6} 4 d^{10} 5 s^{2} 5 p^{3} ) |
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| 123 | A neutral atom of certain elements has 15 electrons. How many unpaired electrons does it have? ( A ) B. 3 ( c cdot 5 ) D. |
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| 124 | A cricket ball of ( 0.5 mathrm{kg} ) is moving with a velocity of ( 100 mathrm{ms}^{-1} ). The wavelength associated with its motion is: A. ( 1 / 100 mathrm{cm} ) B. ( 66 times 10^{-34} ) m D. 6.6 ( times 10^{-28} mathrm{m} ) |
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| 125 | If the given four electronic configurations (i) ( n=4, l=1 ) (ii) ( n=4,1=0 ) (iii) ( n=3,1=2 ) ( (i v) n=3,1=1 ) are arranged in order of increasing energy, then the order will be: A. (iv) < (ii) < (iii) < (i) B. (ii) < (iv) < (i) < (iii) c. (i) < (iii) < (ii) < (iv) D. (iii) < (i) < (iv) < (ii) |
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| 126 | For a hypothetical ( boldsymbol{H} ) -like atom, the wavelength in ( A^{o} ) for the spectral lines for radiations from ( n=p ) to ( n=1 ) are given by ( lambda=frac{1500 p^{2}}{p^{2}-1} ; ) where ( p= ) ( 2,3,4 dots ) The wavelengths of most energetic photon and least energetic photons (in ( left.A^{o}right) ) during the transition are: ( mathbf{A} cdot 1500,2000 A^{circ} ) B . ( 2000,1500 A^{circ} ) ( mathbf{c} cdot 1000,2000 A^{circ} ) D. ( 2000,1000 A^{circ} ) |
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| 127 | Electron density studies have revealed that ( X ) and ( Y ) have an equal number of electrons.What are ( X ) and ( Y ? ) ( mathbf{A} cdot C a^{+} ) and ( mathbf{K} ) B. ( H^{+} ) and ( mathrm{He} ) c. ( mathrm{cl} ) and ( mathrm{F} ) D. ( O^{-} ) and ( S^{+} ) E. None of the above |
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| 128 | Every matter can be seen. A. True B. False |
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| 129 | The atomic number ( (z) ) of an element is 25. In its ground state, how many electrons are present in the N shell: A . 13 B. 2 c. 15 D. 3 |
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| 130 | Q. 1 Which of the following conclusions could not be derived from Rutherford’s a-particle scattering experiment? (a) Most of the space in the atom is empty (b) The radius of the atom is about 10-10 m while that of nucleus is 10-15 m (c) Electrons move in a circular path of fixed energy called orbits (d) Electrons and the nucleus are held together by electrostatic forces of attraction |
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| 131 | Atomic number of an atom is equal to the A. number of protons B. number of electrons ( c . ) both a and ( b ) D. sum of proton and electron |
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| 132 | The triad of nuclei that is isotonic is : A ( cdot frac{14}{6} C, frac{15}{7} N, frac{17}{9} F ) В ( cdot frac{12}{6} C, frac{74}{7} N, frac{19}{9} F ) C ( cdot frac{14}{6} C, frac{14}{7} N, frac{17}{9} F ) D cdot ( _{6}^{14} C, frac{14}{7} N, frac{19}{9} F ) |
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| 133 | Assertion ( alpha- ) rays have greater ionizing power than ( beta- ) rays. Reason ( alpha- ) particles carry two unit positive charge while ( beta- ) particles carry only one unit negative charge. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 134 | Which of the following transition will emit maximum energy in hydrogen atom? A. ( 4 f rightarrow 2 s ) В. ( 4 d rightarrow 2 p ) ( mathrm{c} .4 p rightarrow 2 s ) D. All have same energy |
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| 135 | Plots for ( 2 s ) orbital are: ( X, Y ) and ( Z ) are respectively ( mathbf{A} cdot R, R^{2} ) and ( 4 pi r^{2} R^{2} ) B ( cdot R^{2}, R ) and ( 4 pi r^{2} R^{2} ) ( mathbf{C} cdot 4 pi r^{2} R^{2}, R^{2} ) and ( R ) D ( cdot R^{2}, 4 pi r^{2} R^{2} ) and ( R ) |
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| 136 | An element ( A ) has electronic configuration ( 2,8,13,2 . ) The number of electrons in the element having ( l=0 ) is: A . 6 B. 8 ( c .5 ) D. 4 |
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| 137 | The energy of an electron in the first Bohr orbit of H-atom is -13.6 eV. The possible energy value(s) of the excited state(s) for electrons in Bohr orbits of hydrogen is: A. ( -3.4 e V ) в. ( -4.2 e V ) c. ( -6.8 e V ) D. ( +6.8 e V ) |
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| 138 | Which of the following is Heisenberg uncertainty principle? A ( cdot Delta x cdot Delta p geq frac{h}{4 pi} ) в. ( Delta x . Delta p=frac{h}{4 pi} ) c. ( Delta x . Delta p leq frac{h}{4 pi} ) D. ( Delta x . Delta p<frac{h}{4 pi} ) |
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| 139 | is an obsolete scientific model of the atom proposed by J. J. Thomson in 1904. A. Musk melon model B. Plum pudding model c. Christmas melon model D. Pudding model |
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| 140 | Indicate the incorrect statement: A. Number of hybrid orbitals formed is equal to no. of atomic involved B. ( 2 p_{x} ) and ( 2 p_{y} ) – orbitals of carbon can be hybridized to yield two new more stable orbitals C. Effective hybridisation is not possible with orbitals of widely different energies D. The concept of hybridisation has a greater significance in the VB theory of localised orbitals than ( M O ) theory. |
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| 141 | Among the following gaseous elements with atomic numbers, which will have grater rate of diffusion? ( A cdot Z=7 ) B . ( Z=8 ) c. ( Z=10 ) D. ( Z=17 ) |
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| 142 | If a radioactive element ( _{79} A u ) emits ( beta ) particle, what is the new group? ( _{79} A u ) belongs to group I B (copper family)? ( A cdot mid A ) B. IB ( c cdot | A ) D. II B |
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| 143 | Isotopes have similar: A. physical properties B. chemical properties c. mass numbers D. number of neutrons |
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| 144 | The correct order of energy difference between adjacent energy levels in ( H ) atom: ( mathbf{A} cdot E_{2}-E_{1}>E_{3}-E_{2}>E_{4}-E_{3} ) B ( cdot E_{2}-E_{1}>E_{4}-E_{3}>E_{3}-E_{2} ) ( mathbf{c} cdot E_{4}-E_{3}>E_{3}-E_{2}>E_{2}-E_{1} ) D ( cdot E_{3}-E_{2}>E_{4}-E_{3}>E_{2}-E_{1} ) |
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| 145 | Isotopes are the atoms of element having the atomic number but ( _{-}-ldots-_{-} ) mass number |
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| 146 | The difference in number of angular nodes and the number of radial nodes in the orbital to which the last electron of chromium present is |
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| 147 | The oil drop experiment by R.A. Millikan was performed to find A. charge on the neutron B. charge on the electron c. charge on the Proton D. None of these |
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| 148 | The triad of the nuclei that is isotonic is: ( mathbf{A} cdot_{6} N^{14}, 7 N^{14},_{9} F^{19} ) B cdot ( _{6} C^{14}, 7 N^{15},_{9} F^{17} ) ( mathbf{c} cdot_{6} C^{14}_{7} N^{14},_{9} F^{17} ) ( mathrm{D} cdot_{6} C^{12},_{7} N^{14},_{9} F^{19} ) |
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| 149 | Three isotopes of an element have mass numbers, ( M,(M+1) ) and ( (M+2) . ) If the mean mass number is ( (M+0.5) ) then which of the following ratios may be accepted for ( M,(M+1),(M+2) ) in that order? A. 1: 1: 1 B. 4: 1: 1 ( mathrm{c} .3: 2: 1 ) D. 2: 1: 1 |
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| 150 | An electron and a photon each have a wavelength of ( 1.00 mathrm{nm} . ) Find (a) their momenta, (b) the energy of the photon, and (c) the kinetic energy of electron. |
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| 151 | Among the following orbitals which orbital will experience the larger effective nuclear charge? ( 2 s, 3 s, 4 d, 4 f, 3 d, 3 p ) |
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| 152 | An element has average atomic mass ( 20.426 u ) it has 2 isotopes with masses ( mathbf{2 2 . 1 8 2 4} ) and ( mathbf{1 9 . 9 5 7 4 .} ) Calculate the abundance of its isotopes ( X-22 ) and ( X-20 ) |
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| 153 | Which of the following path is assumed for the electron in the theory of Rutherford? A. Elliptical B. Circular c. spiral D. All of the above |
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| 154 | Match the names of the scientists given in column – I with contributions towards the understanding of the atomic structure as given in column-II and choose the correct option from the codes given below: |
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| 155 | Statement 1: Isotopes of a particular element have nearly identical chemical behavior. Statement 2: They have identical electron configurations. A. Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1 B. Both the Statement 1 and Statement 2 are correct, but Statement 2 is NOT the correct explanation of Statement 1. c. statement 1 is correct, but statement 2 is not correct D. Statement 1 is not correct, but Statement 2 is correct |
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| 156 | What transition in the hydrogen spectrum have the same wavelength as Balmer transition ( n=4 ) to ( n=2 ) of ( H e^{+} ) spectrum? |
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| 157 | Which of the following are the limitations of Bohr’s model? (i) It could not explain the intensities or the fine spectrum of the spectral lines. (ii) No justification was given for the principle of quantisation of angular momentum. (iii) It could not explain why atoms should combine to form bond. (iv)It could not successfully applied to single electron atoms. ( A cdot(i),(i i),(i v) ) B . (ii), (iii) c. (i), (iii), (iv) D. (i),(ii),(iii) |
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| 158 | Bohr’s model can explain This question has multiple correct options A. The spectrum of hydrogen atom only. B. Spectrum of an atom or ion containing single electron only. C. The stability of atom. D. The solar spectrum. |
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| 159 | Explain the important features of Rutherford’s Planetary model and write its defects |
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| 160 | 14. The energy required to excite an electron from the ground state of hydrogen atom to the first excited state, is (a) 1.602 x 10-14J (b) 1.69 x 10-16J (c) 1.632 x 10-18 J. (d) 1.656 x 10-20 J |
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| 161 | An electron in the hydrogen atom is excited from the first orbit to the fifth orbit. Find the change in energy of the electron in eV. A ( .+(13.6 times 24) / 25 ) в. ( -(13.6 times 4) / 5 ) C . ( -(0.529 times 4) / 5 ) D. ( -(13.6 times 4) / 9 ) |
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| 162 | 50. If the minimum wavelength obtained in an X-ray 2.5 x 10 m, the operating potential of the tube will (a) 2 kV (b) 3 kV (c) 4 kV (d) 5 kV |
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| 163 | a) An ion with mass number 37 possesses one unit of negative charge. If the ion contains ( 11.1 % ) more neutrons than the electrons. Find the symbol of the ion. b) An electron is in 3d orbitals. Give the possible values of ( n, ) land ( m_{1} ) c) What is the maximum number of emission lines, When the excited electron of a ( boldsymbol{H} ) atom in ( boldsymbol{n}=boldsymbol{6} ) drops to the ground state? |
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| 164 | What is the mass of a lead atom? | 11 |
| 165 | The two p orbitals are deflected by an angle of: A ( cdot 45^{circ} ) B . ( 180^{circ} ) ( c .90^{circ} ) D. ( 120^{circ} ) |
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| 166 | Q. 13 Chlorine exists in two isotopic forms. CL-37 and Cl-35 but its atomien mass is 35.5. This indicates the ratio of Cl-37 and Cl-35 is approximately (a) 1:2 (b) 1 : 1 (c) 1:3 (d) 3:1 Are The free ar |
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| 167 | Order of number of revolution/sec ( gamma_{1}, gamma_{2}, gamma_{3} ) and ( gamma_{4} ) for ( I, ) II, III and IV orbits is: A ( cdot gamma_{1}>gamma_{2}>gamma_{3}>gamma_{4} ) В ( cdot gamma_{4}>gamma_{3}>gamma_{2}>gamma_{1} ) C ( cdot gamma_{1}>gamma_{2}>gamma_{4}>gamma_{3} ) D. ( gamma_{2}>gamma_{3}>gamma_{4}>gamma_{1} ) |
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| 168 | Q41. Symbols 36Br and 79Br can be written, whereas symbols 35Br and 35Br are not acceptable. Answer briefly. Burritton as subscrint while |
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| 169 | In an atom two electrons move around the nucleus in circular orbitals of radii ( R ) and ( 4 R ). The ratio of the time taken by them to complete one resolution is: A . 1: 4 B. 4: 1 ( c cdot 1: 8 ) D. 8: 7 |
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| 170 | The correct size for quanta for different contributions of energy for gaseous molecules is : A. electronic > vibrational > rotational > tranlational B. electronic < vibrational < rotational electronic >rotational > tranlational D. rotational > vibrational > translational > electronic |
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| 171 | On the basis of Rutherford’s model of an atom, which sub-atomic particle is present in the nucleus of an atom? A. Protons B. Electrons c. Neutrons D. All of the above |
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| 172 | Which of the following statement is not correct? A. Atomic no.of A,B,C are 40,57,105 respectively 3. Group no of ( A, B, C ) are IV ( B ), III ( B ) and ( V B ) respectively c. Period no of ( A, B, C ) are 4 th ( , 5 ) th and 6 th respectively D. ( mathrm{C} ) is a radioactive element |
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| 173 | Explain with examples: (i) Atomic number (ii) Mass number, (iii) Isotopes and (iv) Isobars. Give any two uses of isotopes. |
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| 174 | Which of the following is/are example(s) of induced radioactivity reaction? Select correct statement(s) A. Photon or particle is ionised and collected by the positive electrode in a Geiger counter B. A scintillation counter contains a phosphor, a substance that emits a flash of light when struck by a photon or particle. c. Both of the above D. None of the aobve |
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| 175 | If first ionisation energy of hydrogen is ( boldsymbol{E}, ) then the ionisation energy of ( boldsymbol{H} boldsymbol{e}^{+} ) would be: A. ( E ) в. ( 2 E ) ( c .0 .5 E ) D. ( 4 E ) |
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| 176 | According to Schrodinger model, nature of electron in an atom is as: A. particles only B. wave only c. both simultaneously D. sometimes wave and sometimes particle |
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| 177 | The periods of the periodic table are numbered according to ……………….ofthe valence shell. A. azimuthal quantum number B. principal quantum number C. magnetic quantum number D. spin quantum number |
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| 178 | Which two orbitals are located along the axis, and not between the axis? ( mathbf{A} cdot d_{x^{2}-y^{2}}, d_{z^{2}} ) B . ( d_{x y}, p_{z} ) ( mathbf{c} cdot d_{y z}, p_{x} ) D. ( d_{y z}, d_{x^{2}-y^{2}} ) |
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| 179 | Bohr’s theory is applicable to This question has multiple correct options ( mathbf{A} cdot H e^{+} ) ion B. ( L i^{2+} ) ion C . Tritium ( _{1} H^{3} ) ( mathbf{D} cdot_{1} H^{1} ) |
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| 180 | The wave number for the shortest wavelength transition in the Balmer series of atomic hydrogen is : A . ( 8225714 mathrm{m}^{-1} ) В. ( 1523693 m^{-1} ) ( mathbf{c} cdot 5333 c m^{-1} ) D. ( 27419 mathrm{cm}^{-1} ) |
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| 181 | Answer the following questions for Zn atom: How many electrons have ( l-m=1 ? ) |
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| 182 | The line spectrum is noticed during the transition of an electron from higher excited state to lower one in ( boldsymbol{H} ) -atom only when an electron falls from: A . ( 2 s ) -orbital to ( 1 s ) -orbital B. 2p-orbital to 1s-orbital c. ( 3 s ) -orbital to ( 2 p ) -orbital D. ( 4 p ) -orbital to ( 2 p ) -orbital |
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| 183 | A tube of light emits light of wavelength ( mathbf{5 2 9 6} ) A. The bulb is rated as 200watt and ( 20 % ) of the energy is converted into light. If the whole light emitted is allowed to fall on a metal surface having work function ( 3.00 times 10^{-19} J ) calculate the no. of electrons ejected in ( mathbf{1 0} boldsymbol{s} ) |
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| 184 | Boron occurs in nature in the form of two isotopes having atomic mass 10 and ( 11 . ) Calculate the percentage abundances of two isotopes respectively in a sample having atomic mass 10.80 A . 10,90 B. 30, 70 c. 20,80 D. 25,75 |
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| 185 | Which of the following disapproved Thomson’s model? A. The nuclear model of an atom B. The electron model of an atom c. The atomic model of an atom D. None of above |
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| 186 | If in the ground state an atom has seven valence electrons, which of the following is the correct electronic configuration of the atom in the ground state? A ( .3 s^{1} 3 p^{6} ) В. ( 3 s^{6} 3 p^{text {। }} ) c. ( 3 s^{1} 3 p^{4} 3 d^{2} ) D. ( 3 s^{3} 3 p^{4} 3 d^{1} ) E ( .3 s^{2} 3 p^{5} ) |
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| 187 | Which of the following is/are derived by Hisenberg in his uncertainty principle? A ( cdot Delta p times Delta x=frac{h}{4 pi} ) B . ( triangle v times triangle x=frac{h}{4 pi m} ) C ( cdot triangle E times Delta t=frac{h}{4 pi} ) D. ( Delta p times Delta E=frac{h}{4 pi} ) |
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| 188 | What happens when both of the orbitals in a molecule are in phase, either both positive or both negative and the electrons in the bonds are at their lowest energy level? A. Bonding takes place. B. The chemicals don’t react. c. The atoms don’t bond D. Bonding doesn’t take place. E. The electrons in the atoms don’t share orbitals |
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| 189 | In a certain electronic transition in the hydrogen atoms from an initial state (1) to a final state (2), the difference in the orbital radius ( left(r_{1}-r_{2}right) ) is 24 times the first Bohr radius. Identify the transition. ( A cdot 5 rightarrow 1 ) B. 25 ( rightarrow 1 ) ( c cdot 8 rightarrow 3 ) ( D cdot 6 rightarrow 5 ) |
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| 190 | ANCI 1. If 13.6 eV energy is required to ionise a hydrogen atom, then the required energy to remove an electron from n=2 is (a) 10.2 eV (b) O eV (c) 3.4 eV (d) 6.8 eV (AIEEE 2002) |
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| 191 | What is the energy in ( e V ) required to excite the electron from ( n=1 ) to ( n=2 ) state in hydrogen atom? ( (n= ) principal quantum number) A . 13.6 в. 3.4 c. 17 D. 10.2 |
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| 192 | The proton is heavier than an electron by A. 1835 times B. 18000 times c. 1000 times D. 100 times |
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| 193 | An orbital with ( l=0 ) is Symmetrical about the : A. ( x- ) axisonly B. ( y- ) axisonly c. ( z- ) axisonly D. nucleus |
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| 194 | By charging the metal electrodes and gas inside the cathode ray tube: A. the electron particle were produced B. the proton particle were produced c. the neutron particle were produced D. none of the above |
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| 195 | Which of the following force balance the electrostatic force of attraction between the positively and negatively charged particles in Rutherford model? A. The negatively charge particles repulsion. B. The high velocity of the electrons moving in circular path c. The linear movement of the nucleus D. None of these |
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| 196 | What will be the energy of one photon of radiation whose frequency is ( 5 times ) ( 10^{14} H z ? ) A. ( 199.51 J ) в. ( 3.3 times 10^{-19} mathrm{J} ) c. ( 6.626 times 10^{-34} J ) D. ( 2.31 times 10^{5} J ) |
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| 197 | Moseley’s equation is represented as ( sqrt{boldsymbol{v}}=boldsymbol{a}(boldsymbol{Z}-boldsymbol{b}) ) where a and b are constants If ( boldsymbol{O} boldsymbol{A}=mathbf{1}, ) then atomic number of the elements showing frequency of ( 400 H z ) is? A . 2 ( B ) ( c .40 ) 0.19 |
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| 198 | Assertion Isotopes of an element have same chemical properties Reason Chemical properties do not depend on the number of neutrons A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 199 | State True or False. ( H^{2} ) is more reactive than ( H^{1} ) A. True B. False |
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| 200 | According to Bohr theory, the angular momentum of electron in 5 th orbit is: A ( cdot_{25} frac{h}{pi} ) в. ( _{1} frac{h}{pi} ) ( mathrm{c} cdot_{10} frac{h}{pi} ) D. ( _{2.5} frac{h}{pi} ) |
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| 201 | If the threshold energy for ejection of electron from metal is 1.4 eV and light of 3eV falls on the metal, then the kinetic energy of photoelectron emitted will be: A ( .2 .6 times 10^{-19} mathrm{J} ) В. ( 1.6 times 10^{-18} mathrm{J} ) c. ( 2.2 times 10^{-19} mathrm{J} ) D. ( 3.2 times 10^{-20} mathrm{J} ) |
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| 202 | What are the limitations of Rutherford’s nuclear model? A. Electrons should undergoes spiral path and fall into nucleus B. Could not explain hydrogen spectrumm c. Electron lose energy while in motion D. All of these |
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| 203 | The two particle ( A ) and ( B ) have de Broglie wavelengths 1 nm and 5 nm respectively. If mass of ( A ) is 4 times that of mass of ( B ) the ratio of KE of ( A ) and ( B ) would be: A . 5: B. 25: 4 ( c cdot 20: 1 ) D. 5: 4 |
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| 204 | The orbital diagram which violates the aufbau principle’ is: ( A ) ( 2 s ) ( boldsymbol{2 p} ) ( uparrow downarrow ) ( uparrow downarrow quad uparrow ) в. ( 2 s ) 一 2 ( uparrow ) ( uparrow downarrow quad uparrow quad uparrow ) ( c ) ( 2 s ) ( 2 p ) ( uparrow downarrow ) ( uparrow quad uparrow quad uparrow ) D. ( 2 s ) ( prec 2 p ) Why ( uparrow downarrow ) ( uparrow downarrow|uparrow downarrow| uparrow ) |
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| 205 | If the above radial probability curve indicates ‘2s’ orbital, the distance between the peak points ( boldsymbol{X}, boldsymbol{Y} ) is: A ( .2 .07 hat{k} ) в. 1.59 . ( .0 .53 AA ) ( .2 .12 hat{k} ) |
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| 206 | What is meant by the statement that “the atomic number of sodium is eleven”? |
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| 207 | A hydrogen like species (atomic number ( Z ) ) is present in a higher excited state of quantum number ( n ). This excited atom can make a transition to the first excited state by successive emission of two photons of energies ( 10.20 e V ) and ( 17.0 e V ) respectively. Alternatively, the atom from the same excited state can make a transition to the second excited state by successive emission of two photons of energy ( 4.25 e V ) and ( 5.95 e V ) respectively. Determine the value of ( Z ). A . 1 B. 2 ( c cdot 3 ) D. 4 |
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| 208 | Which of the following statements is false? A. Photon has momentum as well as wavelength B. Frequency of emitted radiation from a lower wavelength to higher wavelength as the temperature increases C. Rydberg constant has unit of energy D. Splitting of spectral lines an electrical field is called Stark effect |
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| 209 | Angular momentum of an electron is quantized according to: A. Planck B. Rutherford c. Bohr D. Thomson |
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| 210 | 18. A photon of wavelength 4400 X is passing through vacuum. The effective mass and momentum of the photon are respectively (a) 5 x 10-36 kg, 1.5 x 10-27 kg-m/s (b) 5 x 10-35 kg, 1.5 x 10-26 kg-m/s (c) Zero, 1.5 x 10-26 kg-m/s (d) 5 x 10-36 kg, 1.67 x 10-48 kg-m/s |
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| 211 | The quantum theory is a suggestion that heat, light, electricity or any other form of energy. A. Cab be if any size B. Exist in discrete bundles c. Is continuous D. Is transfered in as small amount as one could imagine |
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| 212 | An electron make transition from orbit number ( N ) to ( P^{t h} ) orbit in ( H- ) atom and emit the photon of wavelength ( (lambda) . ) In orbit ( boldsymbol{P}, ) velocity of electron in ( boldsymbol{H}- ) atom is maximum. Which of the following wavelength ( (lambda) ) is not possible? (Where ( 1 / R=912 A) ) ( mathbf{A} cdot 1216 stackrel{circ}{A} ) B . 972.8 A ( c cdot 1026^{circ} ) D. 3973 h |
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| 213 | Maximum number number of electron that may be present on a ( 4 f ) -orbital is: ( A cdot 2 ) B. 4 c. 7 D. 14 |
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| 214 | Rutherford said that electrons revolve around the nucleus in circular paths called: A . circles B. orbits c. wheels D. sphere |
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| 215 | Atoms may be regarded as comprising of protons, neutrons and electrons. If the mass attributed to a neutron were halved and that attributed to the electron were doubled, the atomic mass of ( frac{12}{6} mathrm{C} ) would: A. remain approximately the same B. be approximately doubled c. be approximately halved D. be reduced approximately by 25% |
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| 216 | . 40 The effect of uncertainty principle is significant only for motion of microscopic particles and is negligible for the macroscopic particles. Justify the statement with the help of a suitable example. |
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| 217 | The momentum of electron is: A. directly proportional to wavelength B. inversly proportional to wave number C. inversly proportional to wavelength D. cannot be determined |
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| 218 | In ground state of chromium atom ( (Z=24) ) the total number of orbitals populated by one or more electrons is?? A . 15 B . 16 c. 20 D. 14 |
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| 219 | What is the new quantum number proposed by Sommerfeld? A. Principal B. spin c. Azimuthal D. Magnetic |
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| 220 | 2. In the hydrogen atom, when electron jumps from second to first orbit, then energy emitted is (a) -13.6 eV (b) -27.2 eV (c) -6.8 eV (d) None of these (AIEEE 2002) |
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| 221 | Number of nodal planes in ( 4 p ) suborbit will be: A . B. ( c cdot 2 ) D. |
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| 222 | The e/m ratio is maximum for: A . ( D^{+} ) в. ( H e^{+} ) ( mathrm{c} cdot H^{+} ) D. ( H e^{2+} ) |
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| 223 | A single electron orbit around a stationary nucleus of charge +Ze where ( mathrm{Z} ) is the atomic number and ‘e’ is the magnitude of the electric charge. The hydrogen-like species required ( 47.2 e v ) to excite the electron from the second Bohr orbit to the third Bohr orbit. The value of ( Z ) is: A. 5 B. 3 ( c cdot 2 ) ( D ) |
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| 224 | Angle between p orbitals is: A ( cdot 90^{circ} ) B . ( 180^{circ} ) ( c cdot 120^{circ} ) D. ( 109^{circ} 28 ) |
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| 225 | Which of the following properties of atom could be explained correctly by Thomson model of atom? A. Overall neutrality of atom. B. Spectra of hydrogen atom. c. Position of electrons, photons and neutrons in atom. D. Stability of atom. |
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| 226 | A small amount of solution containing ( ^{24} mathrm{Na} ) radio nuclide with activity ( boldsymbol{A}= ) ( 2 times 10^{3} ) dps was administered into blood of a patient in hospital. After 5 hour, a sample of the blood drawn out from the patient showed an activity of 16 dpm per cc. ( t_{1 / 2} ) for ( ^{24} mathrm{Na}=15 ) hr. The activity of blood sample drawn after a further time of 5 hr is : A. 0.2118 dpm per ( m L ) B. 0.4232 dps per ( m L ) c. 0.4232 dpm per ( m L ) D. 0.2118 dps per ( m L ) |
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| 227 | Which of the following sets of quantum numbers is correct for an electron in ( 3 d ) orbital? A ( cdot n=3, l=2, m=-3, s=+frac{1}{2} ) в. ( n=3, l=3, m=+3, s=-frac{1}{2} ) c. ( n=3, l=2, m=-2, s=+frac{1}{2} ) D. ( n=3, l=2, m=-3, s=-frac{1}{2} ) |
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| 228 | Q. 22 Arranges, p and d subshells of a shell in the increasing order of effective nuclear charge (Zeff) experienced by the electron present in them. |
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| 229 | The sum of all the quantum numbers of helium atom is : | 11 |
| 230 | Statement 1: Gas-phase elements absorb or emit only specific wavelengths of visible light when excited by an electric current. Statement 2: The energy levels that electrons can occupy in gas-phase atoms and molecules are continuous. A. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1 B. Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1. c. Statement 1 is correct but Statement 2 is not correct. D. Statement 1 is not correct but Statement 2 is correct. E. Both the Statement 1 and Statement 2 are not correct. |
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| 231 | 9. Select the correct statement(s). (a) Electromagnetic radiation is a form of energy consisting of oscillating electric and magnetic fields. (b) Visible light is a form of electromagnetic radiation (c) The electromagnetic spectrum of sunlight received at the Earth’s surface differs from that emitted by the Sun (d) Ultraviolet radiation is absorbed in the stratosphere by ozone and oxygen |
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| 232 | The active mass of ( 7.0 mathrm{g} ) of nitrogen in a ( 2.0 L ) container would be: A . 0.25 B. 0.125 ( c .0 .5 ) D. 14.0 |
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| 233 | 6. Which of the following transitions in hydrogen atoms emits photons of the highest frequency? (a) n = 6 to n = 2 (b) n= 2 to n=1 (c) n=1 to n = 2 (d) n= 2 to n= 6 (AIEEE 2007) |
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| 234 | The spectrum of a molecule is so detailed that a molecule can be identified by its spectrum. A. Only if it is small B. Only by test-tube analysis c. with great difficulty D. Easily, like a fingerprint |
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| 235 | 7. The maximum angular speed of the electron of a hydrogen atom in a stationary orbit is (a) 6.2 x 10′) rad s (b) 4.1 x 101 rad s (c) 24 x 100 rad s-1 (d) 9.2 x 10° rad s- |
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| 236 | The mass number of an atom is slightly less than the actual atomic mass. Give reasons. |
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| 237 | Which of the statements are the drawbacks of Rutherford’s model of an atom? A. The orbital revolution of the electron is not expected to be stable B. Any particle in a circular orbit would undergo a acceleration and the charged particles would radiate energy c. The revolving electron would lose energy and finally fall into the nucleus D. All of the above |
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| 238 | Thomson proposed the model of an atom similar to : A. christmas tree B. christmas pudding c. chocolate D. none of the above |
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| 239 | Q29. Using sp and d notations, describe the orbitals with following quantum numbers : (a) n = 1, 1 = 0, (b) n = 4,1 = 3. (c) n = 3,1 = 1, (d) n = 4, 1 = 2 1111111111 |
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| 240 | ( boldsymbol{alpha}- ) rays are composed of: A. fast moving protons B. fast moving electrons C. the same particles that constitute positive rays D. particles with four mass units and two positive charges |
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| 241 | K shell of ( _{7}^{14} N ) has 2 electrons. How many electrons are present in the shell ? |
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| 242 | Which of the following statements is incorrect? A. Number of electron for ( n+l=5 ) in ( C o^{+3} ) ion is six B. In electronic configuration of Mn, electrons having value of ( m+l=0 ) are 13 C. Three radial nodes are present in the spherically symmetrical orbital of the fourth main shell D. None of the above |
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| 243 | Find the minimum uncertainty in the position of proton when ( u_{p r o t o n}=0.01 times ) speed of light. A ( cdot 3.15 times 10^{3} m ) В. ( 13.2 times 10^{-14} mathrm{m} ) c. ( 6.6 times 10^{-14} m ) D. ( 1.05 times 10^{-14} m ) |
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| 244 | The shortest and longest wave number in ( mathrm{H} ) spectrum of Lyman series is ( (mathrm{R}= ) Rydberg constant): A ( cdot frac{3}{4} ) R, R в. ( frac{1}{R}, frac{4}{3}, ) R c. ( _{R, frac{4}{3} R} ) D. ( _{R,} frac{3}{4} R ) |
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| 245 | ng 1. 0 10 3. Imagine an atom made up of a proton and a hypothetical particle of double the mass of the electron but having the same charge as the electron. Apply the Boh’r atom model and consider all possible transitions of this hypothetical particle to the first excited level. The longest wavelength photon that will be emitted has wavelength 2 (given in terms of the Rydberg constant R for the hydrogen atom) equal to (a) 9/(5R) (b) 36/(5R) (c) 18/(5R) (d) 4/R |
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| 246 | A potential difference of ( 20 K V ) is applied across an ( X-r a y ) tube. Find the minimum wavelength of ( boldsymbol{X}-boldsymbol{r} boldsymbol{a} boldsymbol{y} ) generated |
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| 247 | 8. The transition from the state n = 4 to n = 3 in a hydrogen like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition from (a) 21 (b) 3 → (c) 4 → 2 (d) 5 4 (AIEEE 2009) |
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| 248 | What is the de Broglie wavelength of (a) a bullet of mass ( 0.040 mathrm{kg} ) travelling at the speed of ( 1.0 mathrm{km} / mathrm{s} ) (b) a ball of mass ( 0.060 mathrm{kg} ) moving at a speed of ( 1.0 mathrm{m} / mathrm{s}, ) and (c) a dust particle of mass ( 1.0 times 10^{9} k g ) drifting with a speed of ( 2.2 mathrm{m} / mathrm{s} ? ) |
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| 249 | Which among the following transitions will give Lyman series in Hydrogen emission atomic spectra? ( A cdot K ) to ( L ) B. L to M, N etc c. к to L, M, N etc D. L, M, N etc to K |
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| 250 | Write the range of frequencies of electromagnetic waves which propagate through sky wave mode. | 11 |
| 251 | Copper has 29 electrons and 35 neutrons. Find the atomic mass. A . 62 B. 63 ( c cdot 54 ) ( D cdot 64 ) |
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| 252 | All atoms contain neutrons in their nuclei except: A. Protium B. Helium c. Neon D. Chlorine |
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| 253 | Isotopes of an element have: This question has multiple correct options A. the same physical properties. B. same chemical properties. C. different number of neutrons. D. different atomic numbers. |
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| 254 | Two atoms are said to be isobars if ? A. They have same atomic number but different mass number B. They have same number of electrons but different number of neutrons C. They have same number of neutrons but different number of electrons D. Sum of the number of protons and neutrons is same but the number of protons is different. |
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| 255 | Which of the following species has (have) five unpaired electrons? This question has multiple correct options A . cs в. мп ( c cdot M n^{2+} ) D. ( mathrm{Fe}^{2} ) |
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| 256 | In which pairs do both species have the same number of unpaired electrons in ( mathrm{p} ) orbitals? 10 and ( C l^{+} ) 2. ( F^{+} ) and ( G a^{-} ) 3. ( mathrm{N} ) and ( boldsymbol{K} boldsymbol{r}^{boldsymbol{3}+} ) A. 1,2 and 3 are correct B. 1 and 2 only are correct c. 2 and 3 only are correct D. 1 only is correct |
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| 257 | 9. Energy required for the electron excitation in Lit from the first to the third Bohr orbit is (a) 12.1 eV (b) 36.3 eV (c) 108.8 eV (d) 122.4 eV (AIEEE 2011) |
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| 258 | Spot the mistakes in the given statements and correct them. (a) Lanthanides and actinides are included in the main body of periodic table. (b) Titanium, chromium and manganese are coinage elements. |
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| 259 | Write any two uses of isotopes. | 11 |
| 260 | A square planar complex is formed by hybridization of which atomic orbitals? A ( cdot s, p_{x}, p_{y}, d_{y z} ) B. ( s, p_{x} . p_{y}, d_{x^{2}-y^{2}} ) C ( cdot s, p_{x} cdot p_{y}, d_{z} ) D. ( s, p_{x}, p_{y}, d_{x y} ) |
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| 261 | Which one of the following is not the characteristic of Planck’s quantum theory of radiation? A. The energy is not absorbed or emitted in whole number multiple of quantum B. Radiation is associated with energy C. Radiation energy is not emitted or absorbed continuously but in the form of small packets called quanta D. This magnitude of energy associated with a quantum is proportional to the frequency |
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| 262 | An isotone of ( _{32}^{76} ) Ge is: A ( cdot frac{77}{32} mathrm{Ge} ) B. 家 ( A s ) ( mathrm{c} cdot frac{77}{34} mathrm{Se} ) |
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| 263 | Naturally occurring boron consists of two isotopes whose atomic weights are 10.01 and 11.01. The atomic weight of natural boron is 10.81 . Calculate the percentage of each isotope in natural boron. |
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| 264 | True or False According to JJ. Thomson mode electrons revolve around the nucleus. |
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| 265 | What is the energy of electron in second Bohr’s orbit of ( L i^{2+} ? ) |
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| 266 | An isotone of ( _{32}^{76} ) Ge is: This question has multiple correct options ( mathbf{A} cdot_{32}^{77} G e ) ( mathbf{B} cdot_{33}^{77} A s ) ( mathbf{c} cdot_{34}^{77} S e ) ( mathbf{D} cdot_{34}^{78} S e ) |
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| 267 | Write nuclear reaction equations for: (i) ( alpha ) – decay of ( _{88}^{226} R a ) (ii) ( alpha ) decay of ( _{94}^{242} P uleft(text { iii) } beta^{-} text {- decay of }_{15}^{32} Pright. ) (iv) ( beta^{-} ) – decay of ( _{83}^{210} B i(v) beta^{+}- ) decay of ( _{6}^{11} C ) (vi) ( beta^{+} ) – decay of ( _{43}^{97} T cleft(text { vii) Electron capture of } frac{120}{54} X eright. ) |
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| 268 | The discovery of Balmer and Lyman series was made before proposing model for structure of atom. This question has multiple correct options A. Thomson B. Rutherford c. Bohr D. Planck |
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| 269 | If number of electrons in an atom is 8 and number of protons is also ( 8, ) then ( (i) ) what is the atomic number of the atom ? and (II) what is the charge on the atom? |
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| 270 | The orbital angular momentum of an electron is ( sqrt{3} frac{h}{pi}, ) Which of the following of angular momentum of this electron revolving in unknown Bohr orbit? A ( cdot frac{h}{2 pi} ) в. ( frac{h}{pi} ) ( mathrm{c} cdot_{3} frac{h}{pi} ) D. none of the above |
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| 271 | Ratio of frequency of revolution of electron in second excited state of ( boldsymbol{H} boldsymbol{e}^{+} ) and first excited state of ( boldsymbol{H} ) is ( frac{boldsymbol{2}^{x}}{mathbf{3}^{y}} . ) Then the value of ( x+y ) is: |
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| 272 | In an orbital, the signs of lobes indicate the: A. sign of the wave function B. sign of the probability distribution c. presence or absence or electron D. sign of charge |
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| 273 | How are isotopes of the same element similar? A. They have the same particles in the nucleus B. They have the same number of neutrons C. They are equally abundant in nature D. They have the same number of protons E. They have the same mass |
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| 274 | The MRI (magentic resonance imaging) body scanners used in hospitals operate with ( 400 mathrm{MHz} ) radio frequency energy. The wavelength corresponding to this radio frequency is: A. ( 0.75 mathrm{m} ) B. 0.75 cm c. ( 1.5 mathrm{m} ) D. ( 2 mathrm{cm} ) |
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| 275 | Not considering the electron spin, the degeneracy of second excited state is 9 while the generality of the first excited state of ( boldsymbol{H} ) atom is: A. B. 2 ( c cdot 3 ) ( D ) |
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| 276 | Assertion (A): Hydrogen has one electron in its orbit but it produces several spectral lines. Reason (R): There are many excited energy levels available. A. Both A and R are rue and R is the correct explanation of A B. Both A and R are true and R is not correct explanation of C. A is correct and R is incorrect D. A is incorrect and R is correct |
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| 277 | Q. 17 Identify the pairs which are not of isotopes? (a) ZX, 188 (b) 35x, 327 (c) & X, AY (d) 8X,Y |
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| 278 | Calculate the ratio of moles of ( 3.6 g ) of water and ( 4.4 g ) of carbon dioxide. Atomic mass of ( boldsymbol{C}=mathbf{1 2 u}, boldsymbol{H}= ) ( mathbf{1} boldsymbol{u}, boldsymbol{O}=mathbf{1 6} boldsymbol{u} ) |
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| 279 | An electron has ( u_{r m s} ) value at ( 27^{0} C ) ( left(text { Given } boldsymbol{m}_{e}=mathbf{9 . 1 0 8} times mathbf{1 0}^{-mathbf{3 1}} mathbf{k g}right) ) This question has multiple correct options A. ( 3.7 times 10^{4} m / ) sec B . ( 1.3 times 10^{5} mathrm{km} / mathrm{hr} ) c. ( 1.3 times 10^{5} mathrm{m} / mathrm{sec} ) D. ( 11.7 times 10^{4} k m / h r ) |
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| 280 | Uncertainty in position and momentum are equal. Uncertainty in velocity is: A ( cdot sqrt{h / pi} ) B. ( sqrt{h / 2 pi} ) c. ( 1 / 2 m sqrt{h / pi} ) D. None of these |
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| 281 | Isobars are: A. the atoms of same element having the same atomic number but different mass numbers B. the atoms of same element having different atomic numbers but same mass number C. atoms of different elements with same atomic number which have different mass numbers D. atoms of different elements with different atomic numbers which have same mass number |
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| 282 | Supposing the ionisation energy of hydrogen like species is 960 eV. Find out the value of principal quantum number having the energy equal to – 60 ( mathrm{eV} ) ( A cdot n=2 ) B. ( n=3 ) ( c cdot n=4 ) ( D cdot n=5 ) |
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| 283 | The observation of discrete energy lines suggests that an electron in an atom can have only certain or definite energies. A . True B. False |
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| 284 | All of the following statements are true about Bohr’s model of the atom except which one of the following? A. An electron may assume an infinite number of velocities B. An atom is most stable when its electronic configuration is that of the ground state C. The electron shell numbers represents the principal energy levels D. Electrons in orbitals closest to the nucleus have the lowest energy E. They are all consistent |
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| 285 | Which statement below is not acceptable with the concept of isotopes? A. Each elements is composed of atoms B. All atoms of an element are identical C. The atoms of different elements have different chemical and physical properties D. The combining of elements leads to the formation of compounds E. In a compound, the kinds and numbers of atoms are constant |
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| 286 | Silver crystallises in fcc lattice. If edge length of the cell is ( 4.07 times 10^{-8} mathrm{cm} ) and density is ( 10.5 g mathrm{cm}^{3} ), calculate the atomic mass of silver. |
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| 287 | If number of electrons in an atom is 8 and number of protons is also 8 , then give the atomic number of atom and the charge on the atom. A. (i) Atomic number ( =8, ) (ii) Charge ( =0 ) B. (i) Atomic number ( =4, ) (ii) Charge ( =0 ) c. (i) Atomic number ( =8, ) (ii) Charge ( =+1 ) D. (i) Atomic number ( =4, ) (ii) Charge ( =+1 ) |
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| 288 | Hydrogen atom, unipositive helium, dipositive lithium contain single electron in the same shell. Is the radius of the shell same in all cases? Give reason. |
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| 289 | It was known by 1900 that the atom was not ( a_{dots} dots dots dots, dots ) particle but contained at least one sub-atomic particle the electron identified by J.J. Thomson A. simple, divisible B. complex, indivisible c. simple, indivisible D. complex, divisible |
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| 290 | Which of the following is the electron configuration of a transition metal? A ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} ) B ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} ) C ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} 3 d^{5} ) D ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} 3 d^{10} 4 p^{2} ) |
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| 291 | The blocks of the periodic table are named for the ( ldots ). orbital to be occupied according to the building-up principle. 1. first 2. last 3. highest 4. lowest |
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| 292 | 76. According to Bohr’s theory of hydrogen atom, the product of the binding energy of the electron in the nth orbit and its radius in the nth orbit (a) is proportional to n? (b) is inversely proportional to n’ (c) has a constant value of 10.2 eV-Å (d) has a constant value of 7.2 eV-Å |
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| 293 | The energy of the second Bohr orbit of hydrogen atom is – 3.41 eV. The energy of the second orbit of ( boldsymbol{H} boldsymbol{e}^{+} ) would be: A . – ( 0.85 mathrm{ev} ) B . -13.6ev c. -1.70ev D. – ( 6.82 mathrm{eV} ) |
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| 294 | The value of ‘ ( m_{s} ) ‘ for an electron spinning in clock-wise direction is and for anti-clockwise direction is |
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| 295 | The ratio of ( e / m ) for a cathode ray: A. varies with a gas in a discharge tube B. is fixed C. varies with different electrodes D. is maximum if hydrogen is taken |
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| 296 | Assertion : ( beta- ) particles are deflected more than ( alpha- ) particles in a given electric field. Reason: Charge on ( alpha- ) particles is |
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| 297 | A certain particle carries ( 2.5 times 10^{-16} C ) of static electric charge. Calculate the number of electrons present in it. |
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| 298 | Which electronic level would allow the hydrogen atom to absorbs a photon but not to emit a photon? A . ( 3 s ) B . ( 2 s ) c. ( 1 s ) D. ( 4 s ) |
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| 299 | If a sub-shell is denoted as ( 2 p ) then its magnetic quantum number values are A . – 3, -2, – – B. – -1, 0, + 1 ( c .-2,-1,0 ) D. 0, 1, 2 |
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| 300 | Sub atomic particles of atoms are: A. protons B. electrons c. neutrons D. all of these |
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| 301 | The position of both, an electron and a range of helium atom is known within 1.0 ( n m . ) Further the momentum of the electron is known within a range of ( mathbf{5 . 0} times mathbf{1 0}^{-mathbf{2 6}} mathbf{k g} mathbf{m s}^{-1} . ) The minimum uncertainty in the measurement of the momentum of the helium atom is: A. ( 50 mathrm{kg} mathrm{ms}^{-1} ) B. ( 80 mathrm{kg} mathrm{ms}^{-1} ) c. ( 80 times 10^{-26} ) kg ( m s^{-1} ) D. ( 5 times 10^{-26} mathrm{kg} mathrm{ms}^{-1} ) |
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| 302 | Shape of P-Orbital is: A. spherical B. dumb-Bell c. double dumb bell D. none of these |
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| 303 | The ionization energy of hydrogen atom is ( 13.6 mathrm{eV} ). The energy required to excite the electron in a hydrogen atom from the ground state to the first excited state is: A ( cdot 1.69 times 10^{-18} mathrm{J} ) В. ( 1.69 times 10^{-23} ) 」 c. ( 1.69 times 10^{23} ) 」 D. ( 1.69 times 10^{25} mathrm{J} ) |
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| 304 | Assertion Only one in 20000 of alpha particles deflected in Rutherford’s experiment. Reason Most of the space in the atom is empty. |
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| 305 | Cobalt-60 is used to irradiate tumors with ( gamma ) -rays ( _{27}^{60} C o longrightarrow_{28}^{60} N i+_{-1}^{0} e+gamma ) Which is responsible for destroying cancer-cells? A ( cdot gamma- ) rays В. ( alpha- )rays ( mathbf{c} cdot beta-r a y s ) D. None of these |
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| 306 | Wave number of spectral line for a given transition is ( x c m^{-1} ) for ( H e^{+}, ) then its value for ( B e^{3+} ) (isoelectronic of ( boldsymbol{H} boldsymbol{e}^{+} ) ) for same transition is: A ( cdot frac{x}{4} c m^{-1} ) B. ( x mathrm{cm}^{-1} ) ( c cdot 4 x c m^{-1} ) D. ( 16 x mathrm{cm}^{-1} ) |
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| 307 | Electronic configuration of ( G a ) is A ( cdot[H e] 2 s^{2} 2 p^{1} ) В ( cdot[N e] 3 s^{2} 2 p^{1} ) ( mathbf{c} cdot[K r] 4 d^{10} 5 s^{2} 5 p^{1} ) ( mathbf{D} cdot[A r] 3 d^{10} 4 s^{2} 4 p^{1} ) |
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| 308 | The atomic number of chromium is 24 Its electronic configuration in ground state is ( 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{1} 3 d^{5} ) Chromium atom by losing 3 electrons form ( mathrm{Cr}^{3+} ) ions. A chromium atom contains ( 17 % ) more neutron than the protons. Now answer the following questions The number of unpaired electrons in ( mathrm{Cr} ) ( 3+ ) ions is : ( A cdot 3 ) B. 6 ( c cdot 5 ) D. |
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| 309 | Which of these are the characteristics of wave function ( mathbf{Psi} ? ) This question has multiple correct options A. ( Psi ) must be single valued в. ( int_{-infty}^{+infty} Psi^{2} d x d y d z=1 ) c. ( Psi ) must be finite and continous D. ( Psi ) can be discrete |
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| 310 | Nuclidic masses of ( _{7}^{14} mathrm{N} ) and ( _{7}^{15} mathrm{N} ) are mixed to give average atomic mass of 14.1. The ratio of ( 14 mathrm{N} ) and ( 15 mathrm{N} ) mixed is : 7 7 |
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| 311 | The nucleodic masses of ( ^{14} mathrm{N} ) and ( ^{15} mathrm{N} ) are mixed to give atomic mass of 14.1 What is the ratio of the two isotopes as a whole number |
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| 312 | If ( boldsymbol{H}_{2}, boldsymbol{H} e, boldsymbol{O}_{2} ) and ( boldsymbol{N}_{2} ) tarvel with same velocity then the longest de-Brogile wavelength should be associated with: A ( . H_{2} ) в. ( H e ) ( c cdot O_{2} ) D. ( N_{2} ) |
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| 313 | Two carbon discs of ( 1.0 g ) each are 1.0 ( c m ) apart have equal and opposite charges. If forces of attraction between them is ( 1.00 times 10^{-5} N ), calculate the ratio of excess electrons to total atoms on the negatively charged disc. (permitivity constant is ( 9.0 times 10^{9} N m^{2} ) ( left.C^{-2}right) ) A ( cdot 6.68 times 10^{-33} ) В. ( 1.6 times 10^{-14} ) c. ( 4.17 times 10^{-12} ) D. ( 4.17 times 10^{-14} ) |
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| 314 | Alpha particles are positively charged and contains the nucleus of atom. A. ( H e ) в. ( H ) c. ( L i ) D. ( H^{+} ) |
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| 315 | Suppose the potential energy between electron and proton at a distance r is given by ( -frac{k e^{2}}{3 r^{3}} . ) Use Bohr’s theory to obtain energy of such a hypothetical atom |
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| 316 | A particle of mass ( M ) at rest decays into two particles of masses ( m_{1} ) and ( m_{2} ) having non-zero velocities. The ratio of the de-Brogile wavelengths of the particles, ( frac{boldsymbol{I}_{1}}{boldsymbol{I}_{2}} ) is: A. ( frac{m_{1}}{m_{2}} ) в. ( frac{m_{2}}{m_{1}} ) ( c cdot 1: 1 ) D. ( sqrt{frac{m_{2}}{m_{1}}} ) |
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| 317 | The energy needed to excite a hydrogen atom from its ground state to its third excited state is: A . ( 12.1 e V ) B. ( 10.2 e V ) c. ( 0.85 e V ) D. ( 12.75 e V ) |
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| 318 | Calculate the wavelength (in nanometer) associated with a proton moving at ( 1.0 times 10^{3} m s^{-1} ) (Mass of proton= ( 1.67 times 10^{-27} k g ) and ( boldsymbol{h}=mathbf{6 . 6 3} times mathbf{1 0}^{-mathbf{3 4}} boldsymbol{J} boldsymbol{s} ) A. ( 0.40 n m ) в. ( 2.5 n m ) ( mathrm{c} .14 .0 mathrm{nm} ) D. ( 0.32 n m ) |
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| 319 | Q1. (i) Calculate the number of electrons which will together weigh one gram. (ii) Calculate the mass and charge of one mole of electrons. |
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| 320 | Which two orbitals are located along the axis, not between the axis? ( mathbf{A} cdot d_{x^{2}-y^{2}}, d_{z^{2}} ) B . ( d_{x y}, p_{z} ) ( mathbf{c} cdot d_{y z}, p_{x} ) D ( cdot p_{x}, d_{x^{2}-y^{2}} ) |
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| 321 | What is the colour corresponding to the wavelength of light emitted when the electron in a hydrogen atom undergoes transition from ( n=4 ) to ( n=2 ? ) A. Blue B. Red c. Yellow D. Green |
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| 322 | Calculate the wavelength, frequency and wavelength of a light wave whose time period is ( 2.0 times 10^{-10} )sec | 11 |
| 323 | When a certain metal was irradiated with a light of ( 8.1 times 10^{16} ) Hz frequency, the photoelectron emitted had 1.5 times the kinetic energy as did the photoelectrons emitted when the same metal was irradiated with light ( 5.8 times ) ( 10^{16} mathrm{Hz} ) frequency. If the same metal is irradiated with light of 3.846 nm wavelength,what will be the energy of the photoelectron emitted? A ( .1 .8 times 10^{2} e V ) В. ( 3.65 times 10^{-17} J ) c. ( 2.28 times 10^{2} e V ) D. ( 4.37 times 10^{-17} J ) |
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| 324 | How many nucleons are present in phosphorous? A . 15 B. 16 c. 30 D. 31 |
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| 325 | Which of the following is not true for atomic number? A. It indicates the number of protons in the nucleus B. It is represented usually by z c. It is identical with the mass number D. It is constant for a given element |
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| 326 | Write the electronic configuration of the following elements (a) Sulphur ( (mathrm{Z}=16) ) (b) Krypton ( (z=36) ) |
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| 327 | For which of the following orbital wave function does not change from positive to negative at any distance from nucleus? A . ( 1 s ) в. ( 2 p ) c. ( 2 s ) D. ( 3 d ) |
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| 328 | The total energy of an electron in the ground state of the hydrogen atom is -13.6 eV. The kinetic energy of an electron in the first excited state is: ( mathbf{A} cdot 1.7 mathrm{eV} ) B. 3.4 ev c. 6.8 ev D. 13.6 ev |
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| 329 | 5. de Broglie equation is hv mo (a) 2 = (b) 2 = (c) 2 = (d) a = hmo mn mv TL1 11 |
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| 330 | In Rutherford’s ( alpha ) -particle scattering experiment, a very small fraction of ( alpha ) particles were deflected by ( 180^{circ} . ) What did the conclude from this observation? A. All the positive charge and mass of the atom occupy very little space. B. Most of the space inside the atom is empty c. All the positive charge and mass of the atom were concentrated in a very small volume. D. Both A and B |
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| 331 | Q. 15 For the electrons of oxygen atom, which of the following statements is correct? (a) Zeff for an electron in a 2s orbital is the same as Zef for an electron in a 2p orbital (b) An electron in the 2s orbital has the same energy as an electron in the 2p orbital (c) Zeff for an electron in 1s orbital is the same as Zeff for an electron in a 2s orbital (d) The two electrons present in the 2s orbital have spin quantum numbers m, but of opposite sign |
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| 332 | By using the above informations define the electronic configuration of ( S ) atom. A ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{4} ) B . ( 1 s^{2} 1 p^{6} d^{6} 2 s^{2} ) c. ( 1 s^{2} 1 p^{6} 1 d^{10} ) D. ( 1 s^{2} 1 p^{6} 2 p^{6} 2 d^{2} ) |
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| 333 | Nodal plane is found in which orbital? A ( . n=2, l=0 ) B. ( n=3, l=0 ) c. ( n=2, l=1 ) D. ( n=1, l=0 ) |
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| 334 | The emission spectra of atoms in the gaseous phase do not show a continuous spread of wavelength from red to violet, rather they emit light only at specific wavelengths with dark spaces between them. Such spectra is/are called: A. line spectra B. atomic spectra c. both ( (A) ) and ( (B) ) D. none of these |
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| 335 | The hydrogen-like species ( L i^{2+} ) is in a spherically symmetric state ( S_{1} ) with one radial node and its energy is equal to the ground state energy of the hydrogen atom. The energy of the state ( S_{2}( ) next state ) in units of the hydrogen atom ground state energy is: |
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| 336 | A sample of water is vaporized and tested in a mass spectrometer. There are 3 isotopes of hydrogen, ( 1 H,^{2} H ) and 3. H. There are 2 isotopes of oxygen, ( ^{15} boldsymbol{O} ) and ( ^{16} ) O. How many peaks would be expected to be found on the mass spectrum? |
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| 337 | Consider the outermost electronic configuration of silicon as follow: ( [N e] 3 s^{2} 3 p^{2} ) The given electronic configuration follows: A. Aufbau’s principle B. Paul’s rule c. Hund’s rule D. All of the above |
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| 338 | The transition of electron in H-atom that will emit maximum energy is : A ( cdot n_{3} rightarrow n_{2} ) В . ( n_{4} rightarrow n_{3} ) ( mathbf{c} cdot n_{5} rightarrow n_{4} ) D. all have same energy |
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| 339 | De-Broglie relation describes the relationship of wavelength of an electron with: A . mass B. energy c. momentum D. charge |
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| 340 | Calculate the number of neutrons in ( 18 m L ) of water. (Density of water ( =1 ) ). |
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| 341 | ( L i^{2+} ) ion is in the excited state with wave function of its electron being denoted by the symbol ( Psi_{3,1,0} ). How many radiations of different wavelength will this ( L i^{2+} ) ion will emit upon de- excitation? A. zer B. 6 ( c ) ( D ) |
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| 342 | During ( beta ) -decay, the mass of atomic nucleus: A. decreases by 1 unit B. increases by 1 unitt c. decreases by 2 units D. remains unaffected |
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| 343 | If Hund’s rule is not followed, magnetic moment if ( mathrm{Fe}^{2+} ) is: ( A cdot O ) в. ( frac{h}{2 pi} ) ( c cdot frac{3 h}{2 pi} ) D. ( frac{sqrt{3} h}{4 pi} ) |
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| 344 | State True or False. Carbon-14 dating is used to determine the age of once living material A. True B. False |
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| 345 | Define atomic mass unit. | 11 |
| 346 | suppose that a hypothetical atom gives a red, green,blue and violet line spectrum. Which jump according to figure would give off the red spectral ine A ( .3 rightarrow 1 ) В . ( 2 rightarrow 1 ) ( c cdot 4 rightarrow 1 ) D. ( 3 rightarrow 2 ) |
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| 347 | Calculate the velocity of an electron placed in the third orbit of hydrogen atom. Also calculate the number of revolutions per second that this electron mkaes around the nucleus. |
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| 348 | Which of the following is isoelectronic pair? A. ( C N^{-}, O_{3} ) в. ( C l O_{2}, B r F_{2} ) ( mathrm{c} cdot mathrm{BrO}_{2}^{-}, mathrm{BrF}_{2}^{+} ) D. ( I C l_{2}, C l O_{3} ) |
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| 349 | Q.44 Match the following rules with their statements. Rules Statements A Hund’s Rule 1. No two electrons in an atom can have the same set of four quantum numbers. B. Aufbau Principle 2. Half-filled and completely filled orbitals have extra stability C Pauli Exclusion Principle 3. Pairing of electrons in the orbitals belonging to the same subshell does not take place until each orbital is singly occupied. D. Heisenberg’s Uncertainty 4. It is impossible to determine the exact position and Principle exact momentum of a subatomic particle simultaneously. 5. In the ground state of atoms, orbitals are filled in the order of their increasing energies. |
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| 350 | Which of the following ions is NOT isoelectronic to a noble gas? A ( . A l^{3} ) в. ( K^{+} ) ( c cdot B r^{-} ) D. ( C o^{2} ) |
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| 351 | When alpha particles are sent through a thin metal foil, most of them go straight through the foil because: A. Alpha particles are much heavier than electrons B. Alpha particles are positively charged. c. Most part of the atom is empty D. Alpha particles move with the high velocity |
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| 352 | Lightest isotope in the periodic table is: A. tritium B. deuterium c. protium D. none of these |
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| 353 | Q3. With what velocity must an electron travel so that its momentum is equal to that of a photon of wavelength = 5200 A? |
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| 354 | What is the frequency of light emitted when an electron in a hydrogen atom jumps from 2nd orbit to 1st orbit? | 11 |
| 355 | Q. 29 An atom having atomic mass number 13 has 7 neutrons. What is the atomic number of the atom? |
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| 356 | What do you call the compounds having the same molecular formula but different structural arrangements of atoms? |
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| 357 | What is the frequency of photon whose momentum is ( 1.1 times 10^{-23} k g m s^{-2} ? ) ( mathbf{A} cdot 5 times 10^{13} H z ) В. ( 5 times 10^{17} mathrm{Hz} ) c. ( 0.5 times 10^{18} mathrm{Hz} ) D . ( 5 times 10^{18} mathrm{Hz} ) |
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| 358 | Heisenberg’s uncertainty principle rules out the exact simultaneous measurement of : A. probability and intensity B. energy and velocity c. charge density and radius D. position and velocity |
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| 359 | Analyze the mass spectrum graph. Calculate the average atomic mass of the unknown element: ( A cdot 10.2 a m ) B. 10.5 amu D. 11.0 amu |
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| 360 | Atomic number of element is 19 ( mathbf{A} cdot M g ) в. ( K ) ( c . A r ) D. ( C a ) |
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| 361 | The compound in which cation is isoelectronic with anion is: A . ( N a C l ) в. ( C s F ) c. ( N a I ) D. ( K_{2} ) |
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| 362 | The energy of an electron in second Bohr orbit of hydrogen atom is: A. ( -5.44 times 10^{-19} ) ev B . – 5.44 ( times 10^{-19} ) cal c. ( -5.44 times 10^{-19} mathrm{kJ} ) D. – ( -5.44 times 10^{-19} ) 」 |
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| 363 | Isotopes of an element have: A. same physical properties B. different chemical properties C. different no. of neutrons D. different atomic number |
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| 364 | If nucleons in an excited state fall to a lower energy level, energy is emitted as A. ( alpha- )rays B. ( beta- )rays c. ( gamma- ) rays D. ( X- ) rays |
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| 365 | The minimum energy required for the photo-emission of from the surface of metal is ( 4.95 times 10^{-19} ) J. Calculate the critical frequency and the corresponding wavelength of the photon required to eject the electron. |
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| 366 | The mass number is same as A. atomic mass number B. molecular mass number ( c . ) both a and ( b ) D. None of the above |
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| 367 | The valence configuration of a transition element is ( (n-1) d^{1 rightarrow 10} n s^{1 rightarrow 2} ) The impossible values of ( n ) are: ( A cdot 4,5 ) and 6 B. 1 and 2 c. 2,4 and 6 D. 1,2 and 3 |
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| 368 | Which of the following parameters are the same for all hydrogen-like atoms and ions in their ground states? (a) Radius of the orbit (b) Speed of the electron (c) Energy of the atom (d) Orbital angular momentum of the electron |
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| 369 | Which of the following statements is not correct about the characteristics of cathode rays? A. They starts from the cathode and move towards the anode B. They travel in straight line in the absence of an external electrical or magnetic field C. Characteristics of cathode rays do not depend upon the material of electrodes in cathode ray tube D. characteristics of cathode rays depend upon the nature of gas present in the cathode ray tube |
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| 370 | Which of the following statements is correct for an electron having azimuthal quantum number ( l=2 ? ) A. The electron may be in the lowest energy shell B. The electron is in a spherical orbital C . The electron must have spin ( m_{s}=+frac{1}{2} ) D. None |
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| 371 | 74. A hydrogen atom is in an excited state of principle quantum number n. It emits a photon of wavelength when it returns to the ground state. The value of n is Ta(R-1) (a) VaR(AR-1) (b) / VaR AR (C) (d) (R-1) VaR-1 |
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| 372 | The value of Planck’s constant is ( mathbf{A} cdot 6.627 times 10^{-34} )joulesec. B. ( 6.083 times 10^{-34} ) joulesec. c. ( 6.627 times 10^{-27} ) joulesec. D. ( 6.627 times 10^{-30} ) joulesec. |
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| 373 | A single electron ion has nuclear charge ( +Z e ) where ( Z ) is atomic number and ( e ) is electronic charge. It requires ( 16.52 e V ) to excite the electron from the second Bohr orbit. Find (a) The atomic number of element? (b) The energy required for transition of electron from first to third orbit?? (c) Wavelength of photon required to remove electron from first Bohr orbit to infinity? (d) The kinetic energy of electron in first Bohr orbit? |
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| 374 | Outer electronic configurations of ( boldsymbol{K}, boldsymbol{C u}, ) and ( boldsymbol{C r} ) are respectively : A ( cdot 4 s^{1}, 3 d^{10}, 3 d^{5} ) B . ( 4 s^{2}, 3 d^{10}, 3 d^{4} ) c. ( 4 s^{1}, 3 d^{9}, 3 d^{4} ) D・ ( 4 s^{2}, 3 d^{9}, 3 d^{4} ) |
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| 375 | Element with electronic configuration ( 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} ) is a A . metal B. non-metal c. metalloid D. inert gas |
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| 376 | The ground state energy of hydrogen atom is ( -13.6 e V . ) What is the potential energy of the electron in this state? A ( .0 mathrm{eV} ) B . -27.2 eV ( mathrm{c} cdot 1 mathrm{eV} ) D. 2 eV |
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| 377 | Which of the following statements is incorrect? A. The frequency of radiation is inversely proportional to its wavelength B. Energy of radiation increases with increase in frequency C. Energy of radiation decreases with increase in wavelength D. The frequency of radiation is directly proportional to its wavelength |
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| 378 | The constant of proportionality which relates energy to the frequency of electromagnetic radiation is Planck’s constant and its value is : A ( cdot 06.62 times 10^{-34} J s ) B. ( 3.1 times 10^{-31} J s ) ( mathbf{c} cdot 6.67 times 10^{23} J s ) D. none of these |
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| 379 | The wave number of first line of Balmer series of hydrogen is ( 15200 mathrm{cm}^{-1} . ) The wave number of the first Balmer line of ( L i^{2+} ) ion is: A ( cdot 15,200 mathrm{cm}^{-1} ) В. ( 60,800 mathrm{cm}^{-1} ) c. ( 76,000 mathrm{cm}^{-1} ) D. ( 1,36,800 mathrm{cm}^{-1} ) |
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| 380 | Which of the following gas when taken in the discharge tube produces maximum specific charge of positive rays? A. oxygen B. Nitrogen c. Helium D. Hydrogen |
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| 381 | is a definite path in which the electron revolves round the nucleus A. Orbit B. Circular ring c. orbital D. both ( A ) and ( B ) |
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| 382 | A binary compound between an unknown element ( E ) and hydrogen contains ( 91.27 % E ) and ( 8.73 % H ) by mass. If the formula of the compound is ( boldsymbol{E}_{3} boldsymbol{H}_{8} . ) Calculate the atomic mass of ( boldsymbol{E} ) |
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| 383 | The isotopes ( U^{238} ) and ( U^{235} ) occur in nature in the ratio ( 140: 1 . ) Assuming that at the time of earth formation, they were present in equal ratio, the estimated age of the age of earth will be : (The half-life period of ( U^{238} ) and ( U^{235} ) are ( 4.5 times 10^{9} ) and ( 7.13 times 10^{8} ) years respectively.) A. ( 6.04 times 10^{9} ) years B. ( 6.25 times 10^{9} ) years c. ( 6.59 times 10^{9} ) years D. non of these |
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| 384 | Calculate the atomic number of the element that has 12 neutrons and a mass number of 23 |
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| 385 | Calculate the frequency of light emitted for an electron transition from the sixth to second orbit of the hydrogen atom. In what region of the spectrum does this light occur? |
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| 386 | The de-Broglie’s wavelength of electron present in first Bohr orbit of ‘H’ atom is : A ( cdot 0.529 ) a B ( cdot 4 times 0.529 ) c. ( 2 pi times 0.529 ) 能 D. ( frac{0.529}{2 pi} stackrel{circ}{A} ) |
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| 387 | Which of the following is the nodal plane of ( d_{x y} ) orbital? This question has multiple correct options A. ( x y ) B. YZ ( c cdot z x ) D. All |
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| 388 | State whether True or False: Bohr’s model failed to explain atomic spectra of multi-electron atoms. A. True B. False |
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| 389 | Uncertainty in position is twice the uncertainty in momentum, uncertainty in velocity is A. ( sqrt{frac{h}{pi}} ) B. ( frac{1}{2 m} sqrt{frac{b}{pi}} ) ( c cdot frac{1}{2 m} sqrt{h} ) D. ( frac{1}{2 sqrt{2 m}} sqrt{frac{h}{pi}} ) |
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| 390 | Q.10 Which of the following is responsible to rule out the existence of definite paths or trajectories of electrons? (a) Pauli’s exclusion principle (b) Heisenberg’s uncertainty principle (c) Hund’s rule of maximum multiplicity (d) Aufbau principle |
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| 391 | Chlorine exists in two isotopic forms, ( C l-37 ) and ( C l-35 ) but its atomic mass is ( 35.5 . ) This indicates the ratio of ( C l-37 ) and ( C l-35 ) is approximately: A .1: 2 B. 1: 1 c. 1: 3 D. 3: 1 |
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| 392 | What transition in ( H e^{+} ) ion shall have the same wave number as the first line in Balmar series of H atom? ( mathbf{A} cdot 7 rightarrow 5 ) B . ( 5 rightarrow 3 ) ( c cdot 6 rightarrow 4 ) ( mathbf{D} cdot 4 rightarrow 2 ) |
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| 393 | In the path of the cathode rays, a tungsten metal is placed in the way. Then the rays produced are: A. cathode rays B. anode rays c. ( x ) -rays D. UV rays |
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| 394 | An atom of radium combines with two atoms of chlorine to form RaCl molecule. The radioactivity of ( boldsymbol{R} boldsymbol{a} boldsymbol{C l}_{2} ) will be : A. zero B. one-half of the same quantity of Ra C. one-third of the same quantity of Ra D. as much as that of the same quantity of Ra |
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| 395 | The number of nodal planes ‘5d’ orbital is: A . zero B. one c. two D. three |
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| 396 | 13. The energy of an electron in an excited hydrogen atom is -3.4 eV. Then, according to Bohr’s Theory, the angular momentum of this electron, in J s, is (a) 2.11 x 10-34 (b) 3 x 10-34 (c) 1.055 x 10-34 (d) 0.5 x 10-34 |
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| 397 | The wave motion of electron in a Bohr’s orbit of hydrogen is as shown in diagram. The potential energy of electron in the given orbit of hydrogen atom is: A ( .-3.4 mathrm{eV} ) B. +3.4 ev ( mathbf{c} .-3.02 mathrm{eV} ) D. -1.51 ev |
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| 398 | Both isotopes and isobars differ in their chemical properties. (True/False) | 11 |
| 399 | If ( E_{e}, E_{alpha} ) and ( E_{p} ) represents the kinetic energies of an electron, alpha particle and a proton respectively, each moving with same de Broglie wavelength, then: A ( cdot E_{e}=E_{alpha}=E_{p} ) В . ( E_{e}>E_{p}>E_{alpha} ) c. ( E_{alpha}>E_{p}>E_{e} ) D. ( E_{e}=E_{p}=E_{alpha} ) |
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| 400 | What are the draw backs of Bohrs atomic model? Show that the circumference of the Bohr orbit for the hydrogen atom is an integral multiple of the de Broglie wavelength associated with the electron revolving around the orbit. |
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| 401 | Which point does not pertain to Bohr’s model of atom? A . Angular momentum is an integral multiple of ( h /(2 pi) ) B. The path of the electron is circular C. Force of attraction towards nucleus = centrifugal force D. The energy changes are taking place continuously |
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| 402 | What is the velocity of electron present in first Bohr orbit of hydrogen atom? A ( cdot 2.18 times 10^{5} m / s ) B ( cdot 2.18 times 10^{6} m / s ) C ( .2 .18 times 10^{-18} mathrm{m} / mathrm{s} ) D. ( 2.18 times 10^{-9} mathrm{m} / mathrm{s} ) |
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| 403 | An element has atomic number 17 and mass number ( 37 . ) There are 17 electrons outside the nucleus. Find the number of neutrons in it. A . 20 B . 21 c. 17 D. 37 |
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| 404 | A ( 0.66 mathrm{kg} ) ball is moving with a speed of ( 100 mathrm{m} / mathrm{s} . ) The associated wavelength will be: ( left[h=6.6 times 10^{-34} mathrm{J.s}right] ) A ( cdot 6.6 times 10^{-32} mathrm{m} ) B ( cdot 6.6 times 10^{-34} mathrm{m} ) c. ( 1.0 times 10^{-35} mathrm{m} ) D. ( 1.0 times 10^{-32} mathrm{m} ) |
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| 405 | (2) Magneul werd UUS (2) 100 2. In a sodium atom (atomic number = 11 and mass number = 23) and the number of neutrons is (a) equal to the number of protons (b) less than the number of protons (c) greater than the number of protons (d) none of these |
11 |
| 406 | Two particles ( A ) and ( B ) are in motion. If the wavelength associated with particle ( A ) is ( 5 times 10^{-8} ) m. Calculate the wavelength associated with particle B if its momentum is half of ( A ) A. ( 5 times 10^{-8} mathrm{m} ) B. ( 10^{-5} mathrm{cm} ) ( mathrm{c} cdot 10^{-6} mathrm{cm} ) D. ( 5 times 10^{-8} mathrm{cm} ) |
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| 407 | ( B e^{+3} ) and a proton are accelerated by the same potential,their de-Broglie wavelengths have the ratio: (Assume mass of proton = mass of neutron) ( ^{A} cdot frac{1}{2 sqrt{2}} ) B. 1: 4 c. 1: 1 D. ( 1: 3 sqrt{3} ) |
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| 408 | Which of the following statements concerning Bohr’s model is/are true? This question has multiple correct options A. It predicts that probability of electron near nucleus is more B. Angular momentum of electron in ( H ) atom ( =frac{n h}{2 pi} ) C. It introduces the idea of stationary states D. It explains line spectrum of hydrogen |
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| 409 | Energy levels ( A, B ) and ( C ) of a certain atoms correspond to increasing values of every level i.e., ( boldsymbol{E}_{boldsymbol{A}}<boldsymbol{E}_{boldsymbol{B}}<boldsymbol{E}_{boldsymbol{C}} ). If ( lambda_{1}, lambda_{2} ) and ( lambda_{3} ) are the wavelengths of radiations corresponding to the transitions ( C ) to ( B, B ) to ( A ) and ( C ) to A respectively, then which of the following statements is correct? B. ( lambda_{3}=frac{lambda_{1} lambda_{2}}{lambda_{1}+lambda_{2}} ) c. ( lambda_{1}+lambda_{2}+lambda_{3}=0 ) D. ( lambda_{3}^{2}=lambda_{1}^{2}+lambda_{2}^{2} ) |
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| 410 | A certain negative ion ( X^{-2} ) has in its nucleus 18 neutrons and 18 electrons in its extra nuclear structure. What is the mass number of the most abundant isotope of ‘X’? A. 35.46 B. 32 ( c cdot 36 ) D. 39 |
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| 411 | Which of the following statement is not correct regarding cathode rays? A. Cathode rays originate from the cathoge B. charge and mass of the particles constituting cathode rays depends upon the nature of the gas C. Charge and mass of the particles present does not depend the material of the cathode D. The ratio charge/mass of the particles is much greater than that of anode rays. |
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| 412 | The radial part of the Schrodinger wave equation for hydrogen atom is given below: ( gamma(r)=frac{1}{16 sqrt{4} a_{0}^{3 / 2}}(sigma-1)left(sigma^{2}-8 sigma+right. ) ( mathbf{1 2}) boldsymbol{theta}^{-boldsymbol{sigma} / mathbf{2}} ) Here, ( a_{0}= ) constant, ( sigma=frac{2 r}{n a_{0}} ) and ( n= ) principal quantum number. With respect to the above-given data, select the correct statements. This question has multiple correct options A. Distance of the nearest radial node from the nucleus is ( 2 a_{0} ) B. Distance of the farthest radial node from the nucleus is ( 12 a_{0} ) c. Number of maxima in the curve ( gamma(r) ) vs ( r ) is 4 D. The given equation of ( gamma(r) ) represents ( 4 p ) orbital. |
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| 413 | Find the velocity of photo electron librated by electromagnetic radiation of wavelength ( 18 n m ) from stationary ( H e^{+} ) ion in the ground state. |
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| 414 | An element X occurs in short period having configuration ( n s^{2} n p^{1} ). the formula and nature of its oxide is : A. ( X O_{3, text { basic }} ) в. ( X O_{3} ),bcidic c. ( X_{2} O_{3, text { amphoteric }} ) D. ( X_{2} O_{3, text { basic }} ) |
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| 415 | An electron in ( 2^{n d} ) orbit gains energy and goes to ( 4^{t h} ) orbit. What are the differences in angular momentums experienced by the electron due to the transition? A ( cdot frac{2 h}{pi} ) в. ( frac{h}{2 pi} ) ( c cdot frac{h}{pi} ) D. ( frac{3 h}{4 pi} ) |
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| 416 | Atomic number is denoted by ( A cdot A ) B. ( c cdot z ) D. M |
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| 417 | Identify the true statements(s). This question has multiple correct options A. The electron density in the xy plane in ( 3 d_{y z} ) orbital is zero B. The electron densities in the xy and xz planes in ( 3 d_{y z} ) orbital are zero C. Paulis principle states that the total wave function of two identical fermions is anti-symmetric with respect to exchange of particles D. Paulis principle is not obeyed by bosons |
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| 418 | 18. As the quantum number increases, the difference of en between conservative energy levels: (a) decreases (b) increases (c) first decreases and then increases (d) remains the same |
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| 419 | When an electron makes transition from ( (n+1) ) state, to ( n ) state the wavelength of emitted radiations is related to ( n(n>> ) ( >1), ) according to ( lambda propto n^{x} ). The value of ( x ) is: |
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| 420 | Atoms of two elements ( P ) and ( Q ) have 5 electrons in ( 2^{n d} ) shell and ( 3^{r d} ) shell respectively. What will be the atomic numbers of these elements? A . 4: 15 B. 5: 15 ( c cdot 7: 13 ) D. 7: 15 |
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| 421 | Set of molecules which are isoelectronic is : a) ( N_{2} ) and ( C O ) b) ( C O_{2} ) and laughing gas ( left(N_{2} Oright) ) c) ( mathrm{CaO} ) and ( mathrm{MgS} ) d) Benzene and Borazole ( left(B_{3} N_{3} H_{6}right) ) ( A cdot a, b, d ) B. b, c, d c. ( c, d ) D. ( a, b, c, d ) |
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| 422 | If the de Broglie wavelength of the electron in ( n^{t h} ) Bohr orbit in a hydrogenic atom is equal to ( 1.5 pi a_{0}left(a_{0}right. ) is Bohr radius), then the value of ( n / z ) is: A . 1.0 в. 0.75 c. 0.40 D. 1.50 |
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| 423 | Protons and neutrons are heavier than electrons and reside in the center of the atom, which is called A. the nucleus B. the Orbit c. the orbitals D. none of the above |
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| 424 | Ultraviolet light of ( 6.2 mathrm{eV} ) falls on aluminium surface (work function = 4.2eV). The kinetic energy in joules of the fastest electron emitted is approximately: A ( cdot 3 times 10^{-21} ) B . ( 3 times 10^{-19} ) c. ( 3 times 10^{-17} ) D. ( 3 times 10^{-15} ) |
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| 425 | The radius of an orbit in hydrogen atom is 52.9 A. The angular momentum of the electron in the orbit could be: A ( cdot frac{5 h}{pi} ) в. ( frac{5 h}{4 pi} ) ( c cdot frac{4 h}{2 pi} ) D. ( frac{4 h}{pi} ) |
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| 426 | A neutral atom has a total of 17 electrons. The electron configuration in the outermost principle energy level will look closest to: A ( cdot 1 s^{2}, 2 s^{2}, 2 p^{5} ) B . ( 3 s^{2}, 3 p^{5} ) ( mathbf{c} cdot s^{2}, p^{5} ) D. ( s^{2}, p^{8}, d^{7} ) E ( . s, p^{7} ) |
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| 427 | Choose the correct answer Property of anode rays: A. Travel in straight lines: They cast a shadow of the objects placed in their way. B. Produce mechanical effect: A paddle wheel placed in their path starts rotating. C. Rays are positively charged: Anode rays are deflected towards the negative plate of an electric field. D. All of the above |
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| 428 | The speed of an electron having a wavelength of ( 10^{-10} m ) is : A ( cdot 4.24 times 10^{6} m / s ) B . ( 5.25 times 10^{6} mathrm{m} / mathrm{s} ) c. ( 6.25 times 10^{6} m / s ) D. ( 7.25 times 10^{6} mathrm{m} / mathrm{s} ) |
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| 429 | Number of spectral lines that are emitted by atomic hydrogen excited to the ( n t h ) energy level is: A ( cdot frac{1}{2} n(n-1) ) B . ( frac{1}{4} n(n-1) ) c. ( frac{1}{2} n(n+1) ) D ( cdot frac{1}{2} n(n-2) ) |
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| 430 | Isotopes are the atoms of the different element. A . True B. False |
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| 431 | Which of the following orbitals is not cylindrically symmetrical about ( z ) -axis? ( mathbf{A} cdot 3 d_{22} ) в. ( 4 p_{z} ) ( c cdot 6 s ) D. ( 3 d_{y_{z}} ) |
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| 432 | Neutrons are present in all atoms except? A . не B. ( c cdot H ) D. Ne |
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| 433 | Q. 9 Number of angular nodes for 4d orbital is (a) 4 (b) 3 (c) 2 (d) 1 an |
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| 434 | State True or False. All living organisms contain carbon-14. A. True B. False |
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| 435 | Statement I: Ground state electronic configuration of chromium atom is ( (A r) 4 s^{1} 3 d^{5} ) Statement II: Exchange energy is more wtih ( (boldsymbol{A} boldsymbol{r}) boldsymbol{4} boldsymbol{s}^{1} boldsymbol{3} boldsymbol{d}^{5} ) then ( (boldsymbol{A} boldsymbol{r}) boldsymbol{4} boldsymbol{s}^{2} boldsymbol{3} boldsymbol{d}^{4} ) A. Statement I is true, Statement II is also true Statement is the correct explanation of Statement B. Statementl is true, statement II is also true: Statement II is not the correct explanation of Statement c. statement l is true, Statement II is false D. Statement I is false, Statement II is true |
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| 436 | Spin multiplicity is zero for: ( A ) begin{tabular}{|l|l|l|} hline ( mathbf{1} ) & ( mathbf{1} ) & ( mathbf{1} ) \ hline end{tabular} в. begin{tabular}{|l|l|l|} hline ( mathbf{1} ) & ( mathbf{1} ) & ( mathbf{j} ) \ hline end{tabular} ( c ) ( left|begin{array}{ll}hline mid & downarrow & downarrowend{array}right| ) D. ( sqrt{ }|V| ) |
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| 437 | The argument which favours the particular nature of cathode rays is: A. they produce fluorescence B. they travel through vacuum C. they get deflected by electric and magnetic fields D. they cast shadows of objects present in their way |
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| 438 | If uncertainty in momentum of electron is three times the uncertainty in position, then uncertainty in velocity of electron would be: A ( cdot frac{1}{4 m} sqrt{frac{h}{3 pi}} ) в. ( frac{1}{3 m} sqrt{frac{h}{pi}} ) c. ( frac{1}{3 m} sqrt{frac{4 pi}{h}} ) D. ( frac{1}{2 m} sqrt{frac{3 h}{pi}} ) |
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| 439 | Which of the following is the isotone of ( 16^{3^{32}} ? ) ( mathbf{A} cdot_{15} P^{31} ) В ( cdot_{7} N^{14} ) ( mathbf{c} cdot_{18} A r^{40} ) D ( cdot_{17} C l^{34} ) |
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| 440 | What is the maximum number of emission lines when the excited electron of a ( boldsymbol{H}-boldsymbol{a} boldsymbol{t o m} ) in ( boldsymbol{n}=boldsymbol{6} ) drops to the ground state? |
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| 441 | Which of the properties of the elements is a whole number? A. Atomic mass B. Atomic number c. Atomic radius D. Atomic volume |
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| 442 | Isotopes have same but different A. atomic number, mass number B. atomic mass number, atomic number C. number of neutrons, atomic number D. None of these |
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| 443 | How many orbitals are present in a ( boldsymbol{p} ) subshell? ( mathbf{A} cdot mathbf{3} ) B. ( c cdot 7 ) D. |
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| 444 | An electron has a speed of ( 40 mathrm{m} / mathrm{s} ) accurate up to ( 99.99 % ). what is the uncertainty in locating its position(in ( mathrm{m}) ? ) A. ( 0.0144 mathrm{m} ) B. 0..0258m c. ( 0.0568 mathrm{m} ) D. 0.0395m |
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| 445 | Rutherford’s experiment established that: This question has multiple correct options A. inside the atom there is a heavy positive centre B. nucleus contains protons and neutrons C. most of the space in an atom is empty D. size of nucleus is very small |
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| 446 | Identify the correct option amongst the following: An ( alpha ) particle is : A. a hydrogen molecule B. a helium nucleus c. an electron D. a proton |
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| 447 | 07. What is the wavelength for the electron accelerated by 1.0 x 104 volts? | 11 |
| 448 | The threshold frequency of a metal corresponds to the wavelength of ( x n m ) In two separate experiments ( A ) and ( B ), incident radiations of wavelengths ( 1 / 2 x ) nm and ( 1 / 4 times ) nm respectively are used. The ratio of kinetic energy of the released electrons in experiment B to that in experiment ( A ) is: ( A cdot 1 / 3 ) B. 2 ( c cdot 4 ) ( D .3 ) E. ( 1 / 2 ) |
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| 449 | Suppose the potential energy between electron and proton at a distance r is given by ( -frac{k e^{2}}{r} . ) The value of ( -left(V_{n} / K_{n}right) ) is (Use Bohr’s theory) |
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| 450 | In the third energy level, the number of orbtials are: A. 7 B. 8 ( c cdot 9 ) ( D ) |
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| 451 | A compound has the molecular formula ( X_{4} O_{6} . ) If 10 g of ( X_{4} O_{6} ) has 5.72 g ( X, ) then the atomic mass of ( X ) is : A . 32 amu B. 64 amu c. 67 amu D. 98 amu |
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| 452 | The orbital angular momentum of an electron revolving in a p-orbital is : A . zero в. ( frac{h}{sqrt{2} pi} ) ( c cdot frac{h}{2 pi} ) D. ( frac{1}{2} frac{h}{2 pi} ) |
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| 453 | Which of the following is the parent element of the element ( frac{102}{20} Omega ) if it is formed as a result of ( 3 alpha ) and ( 2 beta^{-} ) decays? A ( cdot frac{90}{16} Gamma ) B . ( frac{114}{24} Phi ) ( mathrm{c} cdot_{28}^{114} mathrm{Theta} ) D. ( _{8}^{12} Delta+_{12}^{90} Xi ) |
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| 454 | The uncertainty in position and velocity of the particle are ( 0.1 n m ) and ( 5.27 times ) ( 10^{-24} m s^{-1} ) respectively then find the mass of the particle ( (boldsymbol{h}=mathbf{6 . 6 2 5} times ) ( 10^{-34} J s^{-1} ) |
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| 455 | The wave length of an electron wave is inversely proportional to and A. mass, density B. mass, velocity c. mass, frequency D. none of these |
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| 456 | The wave number of the first line of Balmer series of H atom is ( 15200 mathrm{Cm}^{-1} ) What is the wave number of the first line of Balmer series of ( L i^{2+} ) ion? A. ( 15200 mathrm{Cm}^{-1} ) B. ( 6080 mathrm{Cm}^{-1} ) c. ( 76000 C m^{-1} ) D. ( 136800 C m^{-1} ) |
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| 457 | In a hydrogen atom, an electronjumps from the second orbit to the first orbit Find out The wavelength of the radiation is : A ( cdot 1.325 times 10^{3} mathrm{A} ) в. ( 2.430 times 10^{3} ) А c. ( 1.215 times 10^{3} ) A D. ( 2.255 times 10^{3} ) A |
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| 458 | When an electron makes a transition from ( (n+1) ) state to ( n ) state, the frequency of emitted radiations is related to n according to ( (n>>1) ) ( A cdot v alpha n^{-3} ) B. ( v alpha n^{2} ) c. ( v alpha n^{3} ) D. ( v alpha ) n ( ^{frac{2}{3}} ) |
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| 459 | Which of the following statements regarding orbitals is false? A. ( 1 s ) orbital has one nodal region. B. ( 2 s ) orbital is spherical with one nodal region. C ( .2 p_{x} ) orbital is dumb bell with one nodal plane. D. ( 3 d_{x y} ) orbital has two nodal planes. |
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| 460 | 9. Which one of the following is isoelectronic with Ne? (b) Mg2+ (c) A1+ (a) N3- (d) all of the above |
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| 461 | These ions differ in their number of electrons by eight : A. ( M g^{+} ) and ( F^{+} ) B. ( L i^{+} ) and ( N e ) ( c cdot O^{2-} ) and ( O^{-} ) D. ( N ) and ( P^{3-} ) E ( cdot C a^{2+} ) and ( C l ) |
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| 462 | The kinetic energy of electrons ejected by using light having frequency equal to threshold frequency ( left(nu_{0}right) ) is: A ( . h v_{0} ) B. almostzero c. very large D. ( h / v_{0} ) |
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| 463 | One of the fundamental particles is missing in one of the isotopes. Then particle and isotope are respectively: A. neutron, protium B. neutron, tritium c. proton, protium D. electron, tritium |
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| 464 | If an electron jumps from orbit ( A ) to orbit ( B ) it loses energy while when it jumps from ( C ) to ( B ) it gains energy. Arrange the orbits in the increasing order of distance from the nucleus. A. ( A<B<C ) B. ( C<A<B ) c. ( C<B<A ) D. ( A<C<B ) |
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| 465 | What transition the hydrogen spectrum would have the same wavelength as the Balmer transition ( n=4 ) to ( n=2 ) of ( boldsymbol{H} boldsymbol{e}^{+} ) spectrum? A ( cdot n_{1}=3, n_{2}=6 ) в. ( n_{1}=2, n_{2}=4 ) c. ( n_{1}=1, n_{2}=2 ) D ( cdot n_{1}=1, n_{2}=4 ) |
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| 466 | ov. An electron in a Bohr orbit of hydrogen atom with the quantum number ny has an angular momentum 4.2176 x 10-34 kg ms. If the electron drops from this level to the next lower level, the wavelength of this line is (a) 18 nm (b) 187.6 pm (c) 1876 Å (d) 1.876 x 104 Å |
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| 467 | The energy of the electron in the first orbit of ( boldsymbol{H} boldsymbol{e}^{-} ) is ( -mathbf{8 7 1 . 6} times mathbf{1 0}^{-mathbf{2 0}} quad boldsymbol{J} . ) The energy of the electron in the first orbit of hydrogen would be: ( begin{array}{ll}text { A } . & -871.6 times 10^{-20}end{array} ) B . ( -435 times 10^{-20} J ) c. ( -217.9 times 10^{-20} mathrm{J} ) D. – ( 108.9 times 10^{-20} mathrm{J} ) |
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| 468 | The absolute charge of the electron is A ( cdot 1.1 times 10^{11} mathrm{C} ) B . ( 1.6 times 10^{14} mathrm{C} ) c. ( 1.6 times 10^{-19} mathrm{c} ) D. ( 6.0 times 10^{-21} mathrm{c} ) |
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| 469 | 19. The ratio of the speed of the electron in the first Bohr of hydrogen and the speed of light is equal to (where and c have their usual meanings in cgs system) (a) 27thcle (b) erh/21c (c) e²cl2rth (d) 2ne²lhc Liinol auntum |
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| 470 | 9. In Bohr’s model of hydrogen atom, let PE represent potential energy and TE the total energy. In going to a higher orbit, (a) PE increases, TE decreases (b) PE decreases, TE increases (C) PE increases, TE increases (d) PE decreases, TE decreases |
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| 471 | Which statement is inconsistent with the concept of isotopes of the same element? A. Isotopes have the same number of protons B. Isotopes have the same atomic number c. Isotopes differ in mass number D. Isotopes differ in number of neutrons present E. Isotopes differ in their nuclear charge |
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| 472 | Q1. The uncertainty in the position of a moving bullet of mass 10 g is 10% m. Calculate the uncertainty in its velocity? |
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| 473 | Answer the following questions for Zn atom: How many electrons have ( n+m=3 ? ) |
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| 474 | During a natural radioactive decay: This question has multiple correct options A. mass number can increase only B. atomic number can increase or decrease C ( . p / n ) can increase or decrease D. number of protons can increase or decrease |
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| 475 | Give reason for the following: The physical properties of isotopes of the same element are not identical |
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| 476 | Rutherford in his atomic model could not explain behaviour of : A. electrons B. protons c. neutrons D. neutrino |
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| 477 | Which of the following configurations represents the most electronegative element? A ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{1} ) B ( cdot 1 s^{2} 2 s^{2} 2 p^{5} ) C ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{5} ) D ( cdot 1 s^{2} 2 s^{2} 2 p^{4} ) |
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| 478 | The probability of finding an electron in ( a d_{x y} ) orbital is maximum: A. parallel to x-axis B. parallel to y-axis c. parallel to x and y-axis D. at an angle of ( 45^{0} ) from ( x ) and ( y ) axis |
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| 479 | The relative atomic mass of an element ( A ) is ( 16.2 . ) There are two isotopes ( _{8}^{16} A ) and ( _{8}^{18} A ) of the element. Calculate the percentage of ( _{8}^{16} A ) present in the element. A. 90% в. 60 % c. ( 45 % ) D. 80% |
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| 480 | When the electronjumps from ( n=5 ) to ( n ) = 2 level, the spectral line observed in the hydrogen spectrum belongs to: A. Balmer series B. Lyman series c. Brackett series D. Pfund series |
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| 481 | In astronomical observations signals observed from the distant stars are generally weak. If the photon detector receives a total of ( 3.15 times 10^{-18} ) J from the radiations of 600 nm. Calculate the number of photons received by the detector. A . 20 B. 10 ( c cdot 8 ) D. |
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| 482 | The probability of finding out an electron at a point within an atom is proportional to the : A. Square of the orbital wave function i, e ( psi^{2} ) B. Orbital wave function i.e. c. Hamiltonian operator i.e.H D. Principal quantum number i.e. |
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| 483 | Bohr’s model explains: A. the spectrum of hydrogen atom only B. the spectrum of any atom or ion having one electron only C. the spectrum of hydrogen molecule D. the solar spectrum |
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| 484 | Suppose that spin quantum number did not exist, such that only one electron could each orbital of a many- electron atom will have. Now the atomic number of the noble gas atoms in this case is: ( A cdot 2 ) B. 10 ( c cdot 9 ) D. none |
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| 485 | A dye absorbs a photon of wavelength lambda and re-emits the same energy into two photons of wavelengths of ( lambda_{1} ) and ( lambda_{2} ) respectively. The wavelength lambda is related with ( lambda_{1} ) and ( lambda_{2} ) as: ( A cdot lambda=frac{lambda_{1}+lambda_{2}}{lambda_{1} lambda_{2}} ) B. ( lambda=frac{lambda_{1} lambda_{2}}{lambda_{1}+lambda_{2}} ) ( c cdot lambda=frac{lambda_{1}^{2} lambda_{2}^{2}}{lambda_{1}+lambda_{2}} ) D. ( lambda=frac{lambda_{1} lambda_{2}}{left(lambda_{1}+lambda_{2}right)^{2}} ) |
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| 486 | Rutherford Model could not explain: A. maxwell’s theory of elctrodynamics B. line spectra of atom C. both ( A ) and ( B ) D. None of these |
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| 487 | Matter consist of particles such as A . ions B. molecules c. atoms D. All of the above |
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| 488 | Match List-I with List-II. | 11 |
| 489 | Electronic configuration of ( M g^{+2} ) is identical with? A . Ne B. Na a c. D. |
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| 490 | Assertion Cathode rays get deflected towards the positive plate of electric field. Reason Cathode rays consist of negatively charged particles known as electrons. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion, B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct. |
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| 491 | Less amount of energy is required to remove s’ electron than ‘p’ electron. A. True B. False |
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| 492 | The energy required to excite the electron in the atom from ( n=1 ) to ( n= ) 2, when the ionization enthalpy of a hydrogen atom is ( 1.312 times 10^{6} J / ) mol will be: (in the unit of ( 10^{5} ) ). A . 8.53 B. 7.51 c. 8.92 D. 9.86 |
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| 493 | A ( 2 p ) -orbital is -1 . A. spherically B. cylindrically ( c cdot ) not D. none of these |
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| 494 | What atomic number of an element ( boldsymbol{X} ) would have to become so that the ( 4 t h ) orbit around ( X ) would fit inside the 1 st Bohr orbit of ( boldsymbol{H}- ) atom? ( A cdot 3 ) B. 4 ( c cdot 16 ) D. 25 |
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| 495 | Bohr proposed his atomic model based on: A. oil drop experiment B. planck’s quantum theory c. ( alpha ) -ray scattering experiment D. experiments on conduction of gases |
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| 496 | a) Explain Heisenberg’s uncertainly principle with mathematical derivation b) Calculate the wavelength, frequency and wave number of light wave whose period is ( 2.0 times 10^{-10} ) sec |
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| 497 | The frequency of radiation emitted when the electron falls from ( n=4 ) to ( boldsymbol{n}=mathbf{1} ) in a hydrogen atom will be : ( left(text { Given, } boldsymbol{h}=mathbf{6 . 6 2 5} times mathbf{1 0}^{-mathbf{3 4}} mathbf{J s}right): ) A ( cdot 3.08 times 10^{15} s^{-1} ) В. ( 2.00 times 10^{16} s^{-1} ) c. ( 1.54 times 10^{17} s^{-1} ) D. ( 1.03 times 10^{14} s^{-1} ) |
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| 498 | Which of the following radiations have least effect on both the photographic plate and zinc sulphide screen? A . ( alpha ) -rays B. ( beta ) -rays c. ( gamma ) -rays D. All have equal effect |
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| 499 | All orbitals in d subshell are degenerate under all conditions. A. True B. False |
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| 500 | State True or False. The s orbital is spherical in shape. A. True B. False |
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| 501 | In Millikan’s oil drop experiment, we make use of: A. Ohm’s law B. Ampere’s law c. Stoke’s law D. Faraday’s law |
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| 502 | The ratio of energy to frequency of electromagnetic radiation is called: A. Bohr’s constant B. Rydberg’s constant c. Plancks constant D. Ritz constant |
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| 503 | The number of water molecules differing in molecular mass formed by hydrogen isotopes and ( ^{1} boldsymbol{H},^{2} boldsymbol{H},^{3} boldsymbol{H} ) and oxygen isotopes ( ^{16} boldsymbol{O},^{17} boldsymbol{O},^{18} boldsymbol{O} ) is ( A cdot 6 ) B. 9 c. 12 D. 18 |
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| 504 | When the electron of a hydrogen atom jumps from ( n=4 ) to ( n=1 ) state, the number of spectral lines emitted will be: A . 15 B. 6 ( c .3 ) ( D ) |
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| 505 | Which among the following is correct about ( gamma- ) rays ? A. High energy electrons B. Low energy electrons c. High energy electromagnetic waves D. High energy positrons |
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| 506 | Assertion If the potential difference applied to an electron is made 4 times, the de Broglie wavelength associate halved. Reason On making a potential difference 4 times, velocity is doubled and hence ( lambda ) is halved. Read the above assertion and reason |
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| 507 | The probability of finding an electron in an orbital is approximately: A . 95% B. 50% c. 60% D. 25% |
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| 508 | Why the nucleus is positively charged? | 11 |
| 509 | An electron in ground state absorbs 1.5 times as much energy required to escape from H atom. The wavelength of electron emitted in ( A^{circ} ) is : A ( .4 .21 A^{circ} ) B . ( 4.71 A^{circ} ) c. ( 3.52 A^{circ} ) D. ( 3.711 A^{circ} ) |
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| 510 | What is the maximum number of emission lines when the excited electron of an ( mathrm{H} ) atom in ( mathrm{n}=4 ) drops to the ground state? A ( cdot 14 ) B. 6 c. 15 D. 10 |
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| 511 | 019. Distinguish between a photon and quantum. | 11 |
| 512 | The ratio of energies of photons with wavelengths ( 2000 A^{0} ) and ( 4000 A^{0} ) is: A ( cdot 1 / 4 ) B. 4 ( c cdot 1 / 2 ) D. 2 |
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| 513 | Maximum number of electrons held in the d orbitals is : ( A cdot 2 ) B. 6 c. 8 D. 10 E. 14 |
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| 514 | 225. An electron is in one of the 3d orbitals. Give the possible values of n, I and m, for this electron | 11 |
| 515 | What does ( psi^{2} ) represents in the quantum model of atom? A. Density of electron B. Probability of finding the electron c. volume of electron D. Distance of electron from Nucleus |
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| 516 | Structures of nuclei of three atoms ( A, B ) and ( C ) are given below : A has 90 protons and 146 neutrons B has 92 protons and 146 neutrons C has 90 protons and 148 neutrons Based on the above data, which of these atoms are isotopes and which are isobars? A. A and C are isotopes; B and C are isobars B. A and B are isotopes; A and C are isobars c. B and C are isobars; A and B are isotopes D. A and C are isotopes; A and B are isobars |
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| 517 | Number of revolution per second made by electron in Bohr orbit is called orbital frequency. If ( boldsymbol{u}_{n}, boldsymbol{r}_{n}, boldsymbol{E}_{n} ) are velocity, radius and energy level of ( n ) th orbit respectively? A ( cdot frac{u_{n}}{2 pi r_{n}} ) B. ( -frac{2 E_{n}}{n h} ) c. ( -frac{2 E_{1}}{n^{3} h} ) D. either of these |
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| 518 | Wave no. of a spectral line for a given transition is ( x mathrm{cm}^{-1} ) for ( H e^{+} ) then its value for ( B e^{3+} ) for the same transition is: A. ( 4 x mathrm{cm}^{-1} ) B. ( x mathrm{cm}^{-1} ) c. ( frac{x}{4} c m^{-1} ) D. ( 2 x mathrm{cm}^{-1} ) |
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| 519 | A light whose frequency is equal to ( 6 x ) ( 10^{14} H z ) is incident on a metal whose work function is ( 2 e V ) ( left(h=6.63 times 10^{-34} J s, 1 e V=1.6 times 10^{-}right. ) The maximum energy of electrons emitted will be: A ( .2 .49 e V ) в. ( 4.49 e V ) c. ( 0.49 e V ) D. ( 5.49 e V ) |
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| 520 | As the principal quantum number increases, the difference of distance of separation between consecutive energy levels: A . Decreases B. Remains the same c. Increases D. Sometimes increases and sometimes decreases |
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| 521 | The mass to charge ratio for ( mathbf{A}^{+} ) ions is ( 1.97 times 10^{-7} mathrm{kg} mathrm{C}^{-1} . ) calculate the mass of A atom |
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| 522 | State True or False. Solutions of Schrodinger equation for ( H ) -atom give the same set of values of the energy levels as does the Bohr’s theory A. True B. False |
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| 523 | An atom contains eleven protons. State its atomic number and the number of electrons it contains. ( A cdot 12,12 ) B. 12,11 c. 11,11 D. 12, 13 |
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| 524 | True or False The radius of energy of Bohr’s orbit is equal to integral multiples of 0.529 |
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| 525 | Effective nuclear charge ( left(Z_{e f f}right) ) for ( a ) nucleus of an atom is defined as: A. Shielding of the outermost shell electrons from the nucleus by the innermost shell electrons B. The net positive charge experienced by electron from the nucleus c. The attractive force experienced by the nucleus from electron D. Screening of positive charge on nucleus by innermost shell electrons |
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| 526 | Ratio of time of electron in first and second orbit of ( boldsymbol{H} ) – atom be: ( mathbf{A} cdot 1: 18 ) B. 1: 8 c. 1: 2 D. 2: 1 |
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| 527 | Match the items in List 1 with those in List 2 List 1:Electronic configuration List 2: Total spin |
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| 528 | Which letter orbital corresponds to ( l= ) 2? A. B. ( c cdot d ) D. E. |
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| 529 | Calculate the energy required to excite two litre of hydrogen gas at 1 atom and ( 298 mathrm{k} ) to the first excited state of atomic hydrogen. The energy for the disassociation of ( mathrm{H}_{2} ) bond is ( 436 mathrm{kJ} ) mol ( -1 . ) Also calculate the minimum frequency of photon to break this bond. A. ( 8.523 times 10^{15} mathrm{Hz} ) В . ( 1.096 times 10^{15} ) Н ( z ) c. ( 1.633 times 10^{15} mathrm{Hz} ) . D. 2.806 ( times 10^{15} mathrm{Hz} ) |
11 |
| 530 | write the general electric configure in periodic table.with example | 11 |
| 531 | Which of the following statement is incorrect according to Thomson’s model of an atom? A. The electrons, in a sphere of positive charge, were like currants (dry fruits) in a spherical Christmas pudding. B. The positive charge in the atom is spread all over like the red edible part of the watermelon. C. The electrons are studded in the positively charged sphere, like the seeds in the watermelon. D. The protons are studded in the positively charged sphere, like the seeds in the watermelon. |
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| 532 | The electron configuration for ( C u ) is ( 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{1} 3 d^{10} ) How many inner core electrons does copper contain? ( mathbf{A} cdot mathbf{1} ) B . 10 c. 18 D. 28 |
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| 533 | Boron has two stable isotopes, ( 10_{B(19 %)} ) and ( ^{11} mathrm{B}(81 %) . ) The atomic mass that should appear for boron in the periodic table is |
11 |
| 534 | The quantum numbers of ( +1 / 2 ) and ( -1 / 2 ) for the electron spin represents A. rotation of electron in clockwise and anticlockwise direction respectively B. rotation of electron in anticlockwise and clockwise direction respectively C. two quantum mechanical states having classical analogue D. two quantum mechanical states having no classical analogue |
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| 535 | UTILL Q4. On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements. in this choll are 6s Af |
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| 536 | If the distance between nuclei is ( 2 x ) ( 10^{-13}, ) the density of nuclear material is: (mass of neuclei ( left.=10^{-27}right) ) ( begin{array}{ll}text { A } cdot 3.21 times 10^{-12} & k g / m^{3}end{array} ) В . ( 1.6 times 10^{-3} mathrm{kg} / mathrm{m}^{3} ) D. ( 1 times 10^{17} mathrm{kg} / mathrm{m}^{3} ) |
11 |
| 537 | Q22. Which of the following are iso-electronic species? Nat, K+, Mg2+, Ca2+, s?-, Ar. + 2+ |
11 |
| 538 | Give any three postulates of Bohr’s theory of atomic model. | 11 |
| 539 | If the speed of light is ( 3.0 times 10^{8} mathrm{m} s^{-1} ) calculate the distance covered by light in 2.00 ns. ( A cdot 0.6 m ) B. 0. 3 ( m ) c. ( 0.9 mathrm{m} ) D. 1.2 ( m ) |
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| 540 | State True or False Isotopes have a same number of electrons and protons in all atoms. A. True B. False |
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| 541 | The orientation of electron orbit is determined by: ( A cdot n ) B. ( l ) ( c cdot m ) D. |
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| 542 | A single electron system has ionization energy ( 11180 k J ) mol ( ^{-1} ). Find the number of protons in the nucleus of the system. |
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| 543 | A beam of specific kind of particles of velocity, ( 2.1 times 10^{7} m / s ) is scattered by a gold ( (Z=79) ) nuclei. Find out specific charge (charge/mass) of this particle if this distance of closest approach is ( 2.5 times 10^{-14} m ? ) ( mathbf{A} cdot 4.84 times 10^{7} C / k g ) B . ( 4.84 times 10^{-7} mathrm{C} / mathrm{kg} ) c. ( 2.42 times 10^{7} mathrm{C} / mathrm{kg} ) ( mathbf{D} cdot 3 times 10^{-12} C / k g ) |
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| 544 | In which of the following is the radius of the first orbit minimum? A. A Hydrogen atom B. A tritium atom C. Triply ionized beryllium D. Double ionized helium |
11 |
| 545 | Which of the following hydrogen like species will have same radius as that of a Bohr orbit of hydrogen atom? A ( cdot n=2, L i^{2+} ) B . ( n=2, B e^{3+} ) C ( cdot mathrm{n}=2, mathrm{He}^{+} ) D. ( n=3, L i^{2+} ) |
11 |
| 546 | The decreasing order of energy for the electrons represented by the following sets of quantum numbers is : 1. ( n=4, l=0, m=0, s=pm 1 / 2 ) ( 2 . n=3,1=1, m=1, s=-1 / 2 ) 3. ( n=3,1=2, m=0, s=+1 / 2 ) 4. ( n=3, l=0, m=0, s=-1 / 2 ) ( A cdot 1>2>3>4 ) B ( .2>1>3>4 ) ( (-3>1>2>4 ) D. ( 4>3>2>1 ) |
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| 547 | Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell? A. Valence principal quantum number (n) B. Nuclear charge c. Nuclear mass D. Number of core electrons |
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| 548 | The total spin resulting from a d ( ^{7} ) configuration is : ( mathbf{A} cdot mathbf{1} ) B. 2 ( c cdot 5 / 2 ) D. 3/2 |
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| 549 | Three different wavelengths of light (1,2 and 3 ) are shined onto the same sodium metal surface. Light 1 and 2 produced photoelectrons while Light 3 did not produce any photoelectrons. Light 2 was able to produce photoelectrons with higher velocities than Light 1 Arrange the lights in order of decreasing wavelength. ( mathbf{A} cdot 3>1>2 ) В. ( 2>1>3 ) c. ( 1>2>3 ) D. ( 3>2>1 ) |
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| 550 | Q5. Which one Fe3+, Fe2+ is more paramagnetic and why? 3+ 11, 12+ aontains |
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| 551 | ( |psi(x, y, z, t)|^{2} ) represents: This question has multiple correct options A. probability of finding the particle in the space B. probability distribution function C . stationary state D. None of these |
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| 552 | Match the shell given in List-I with the value of ( l ) given in List-II. | 11 |
| 553 | Who was the discoverer of neutrons??? A. Ernest Rutherford B. J. J. Thomson c. James Chadwick D. None of the above |
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| 554 | The time taken for an electron to complete one revolution in Bohr orbit of hydrogen atom is : A ( cdot frac{4 m^{2} pi r^{2}}{n^{2} h^{2}} ) в. ( frac{n^{2} h^{2}}{4 m r^{2}} ) c. ( frac{4 pi^{2} m r^{2}}{n h} ) D. ( frac{n h}{4 pi^{2} m r^{2}} ) |
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| 555 | The mathematical expression which is true for the uncertainty principle is: A ( cdot(Delta x)(Delta v) geq frac{h}{4 pi} ) в. ( (Delta E)(Delta x) geq frac{h}{4 pi} ) c. ( (Delta theta)(Delta phi) geq frac{h}{4 pi} ) D. ( (Delta x)(Delta m) geq frac{h}{4 pi} ) |
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| 556 | Assertion The density of ( _{6}^{12} mathrm{C} ) nuclide is about ( 1.8 times 10^{17} k g m^{-3} ) to that of water. Reason The ratio of density of ( frac{12}{6} ) C nuclide and water is about ( 1.8 times 10^{14} k g m^{-3} ) A. Assertionis correct but Reasson is wrong B. Assertion is wrong but Reasson is correct C. Both Assertion and Reason are correct and Reason is the correct explanation of Assertion D. Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion |
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| 557 | Find the value of wave number ( bar{v} ) in terms of Rydberg’s constant, when transition of electron takes place between two levels of ( H e^{+} ) ion whose sum is 4 and difference is 2 ( ^{A} cdot frac{8 R}{9} ) в. ( frac{32 R}{9} ) c. ( frac{3 R}{4} ) D. None of these |
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| 558 | De-Broglie wavelength of electron in ( n ) th orbit of ( boldsymbol{H}- ) atom is ( (mathbf{3 . 1 8} boldsymbol{pi}) boldsymbol{A} . ) The value of ( n ) is: ( A cdot 1 ) B . 2 ( c cdot 3 ) D. 4 |
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| 559 | How many electrons in an atom may have the following quantum numbers: ( boldsymbol{n}=mathbf{4}, boldsymbol{m}_{s}=-frac{mathbf{1}}{mathbf{2}} ) A ( cdot 14 ) B. 16 c. 32 D. 20 |
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| 560 | To what effect potential a proton beam be subjected to give its protons a wavelength of ( 1 times 10^{-10} mathrm{m} ? ) A. 0.0826 volts B. 0.0346 volts c. 0.0567 volts D. 0.0234 volts |
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| 561 | The line spectrum of two elements is not identical because: A. they do not have same number of neutrons B. they have dissimilar mass number C. they have different energy level schemes D. they have different number of valence electrons |
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| 562 | What would you predict for the atomic number of the noble gas beyond ( boldsymbol{R} boldsymbol{n} ), if such an element has sufficient stability to be prepared or observed? Assume that ( g- ) orbitals are still not occupied in the ground state of preceding elements. |
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| 563 | Electron has nearly the equal mass as that of a/an: A. proton B. neutron C. positron D. ( alpha ) -particle |
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| 564 | Nuclei of isotopes differ in: A. Number of protons B. Number of neutrons C. Number of neutrons and protons both D. None of these |
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| 565 | An electron is not deflected on passing through a certain region because: This question has multiple correct options A. there is no magnetic field in that region B. there is a magnetic field but velocity of the electron is parallel to the direction of magnetic field C. the electron is a charge less particle D. none of the above |
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| 566 | The density of nucleus is about times the density of atom. A ( cdot 10^{-14} ) B. ( 10^{12} ) ( c cdot 10^{-8} ) D. ( 10^{10} ) |
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| 567 | The correct set the quantum unpaired electron of chlorine atom is: A ( cdot n=2,1=1, m_{1}=0 ) B . ( n=2,1=1, m_{1}=1 ) c. ( n=3,1=1, m_{1}=1 ) D. ( n=3,1=0, m_{1}=0 ) |
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| 568 | Q. 43 Match the quantum numbers with the information provided by these. Quantum number Information provided A. Principal quantum number 1. Orientation of the orbital B. Azimuthal quantum number 2. Energy and size of orbital C. Magnetic quantum number 3. Spin of electron D. Spin quantum number 4. Shape of the orbital |
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| 569 | Energy of the electron in H-atom is 1.50 tionss as much as energy as the minimum required for its escape (13.6 ev) from the atom. The energy difference between two energy livels is? A . 13.6 ev B. 20.4 ev c. 6.8 ev D. 9.07 ev |
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| 570 | One reason the Bohr model of the atom ultimately failed was because it did not explain why? A. moving electrons have a greater mass. B. accelerating electrons do not emit electromagnetic radiation. c. electrons in greater orbits of an atom have greater velocities D. electrons in the orbits of an atom have negative energies. |
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| 571 | Q Type your question. mechanics. However, it turns out that the treatment of spin angular momentum is closely analogous to the treatment of orbital angular momentum. Spin angular momentum ( = ) ( sqrt{s(s+1)} h ) Orbital angular momentum ( = ) ( sqrt{l(l+1)} h ) Total spin of an atom or ion is a multiple of ( frac{1}{2} . ) Spin multiplicity isa factor to confirm the electronic configuration of an atom or ion.Spin multiplicity ( = ) ( left(2 sum s+1right) ) The orbital angular momentum for a ( 2 p ) electron is: A ( cdot sqrt{3} h ) в. ( sqrt{6} h ) c. zero D. ( sqrt{2} frac{h}{2 pi} ) |
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| 572 | The energy of electron is maximum at: A. nucleus B. ground state C. first excited state D. infinite distance from the nucleus |
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| 573 | The de-Broglie wavelength of a tennis ball of mass ( 60 g ) moving with a velocity of ( 10 mathrm{m} / mathrm{s} ) is approximately (planck’s constant, ( boldsymbol{h}=mathbf{6 . 6 3} times mathbf{1 0}^{-mathbf{3 4}} boldsymbol{J}-boldsymbol{s} ) A ( cdot 10^{-33} m ) В. ( 10^{-31} ) m c. ( 10^{-16} m ) D. ( 10^{-25} mathrm{m} ) |
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| 574 | Which one of the following constitutes a group of the isoelectronic species? A ( cdot C_{2}^{2-}, O_{2}^{-}, C O, N O ) B. ( N O^{-}, C_{2}^{2-}, C N^{-}, N_{2} ) c. ( C N^{-}, N_{2}, C O, C_{2}^{2} ) D. ( N_{2}, O_{2}^{-}, N O^{-}, C O ) |
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| 575 | L shell has how many subshell? ( A cdot 1 ) B. 2 ( c cdot 3 ) D. 4 |
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| 576 | Mass spectrograph helps in the detection of isotopes because they: A. have different atomic masses B. have same number of electrons c. have same atomic number D. have same atomic masses |
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| 577 | ( begin{array}{ll}text { List – I } & text { List – II } \ text { A) Velocity of light } & text { 1) Energy }end{array} ) A) Velocity of light B) Plank’s constant Energy particle 2) Energy packet c) Wavenumber D) The correct match is: ( A cdot A-2, B-3, C-4, D-5 ) B. A-1, B-2, C-3. D-4 C. ( A-2, B-4, C-5, D-1 ) D. A-3, B-4, C-5, D-1,2 |
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| 578 | The number of spectral line obtained in Bohr spectrum of hydrogen atom when an electron is excited from ground level to 5 th orbit is : A . 10 B. 5 ( c cdot 8 ) D. 15 |
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| 579 | Can you locate the electron within ( mathbf{0 . 0 0 5 n m ?} ) |
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| 580 | Obtain an expression for the frequency of radiation emitted when a hydrogen atom de-excites from level n to level ( left(n_{1}right. ) For large ( n ), show that this frequency equals the classical frequency of revolution of the electron in the orbit. |
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| 581 | Assertion: K-shell electron capture is detected by analyzing the wavelength of X-ray emitted. Reason: The wavelength of the X-ray is characteristic of the daughter element and not the parent element. A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion B. Both Assertion and Reason are true but Reason is not the correct explanation of Assertion c. Assertion is true but Reason is false D. Assertion is false but Reason is true E. Both Assertion and Reason are false |
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| 582 | The energy of an electron in the first Bohr orbit is -13.6 ev then find the energy of ( H e^{+} ) in the same Bohr orbit. A. 27.2 ev B. -27.2 ev c. 54.4 ev D. – 54.4 ev |
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| 583 | The mass number of nucleus is: A. Sometimes equal to its atomic number B. Sometimes less than and sometimes more than its atomic number C. Always less than its atomic number D. Always more than its atomic number |
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| 584 | CONCOUVE 24. If the intensity of radiation incident on a photocell be increased four times, then the number of photoelectrons and the energy of photoelectrons emitted respectively become (a) four times, doubled (b) doubled, remains unchanged (c) remains unchanged, doubled (d) four times, remains unchanged |
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| 585 | The central equation of the quantum theory is the Schrodinger equation. If true enter 1 , else enter 0 . | 11 |
| 586 | The configuration ( 1 s^{2} 2 s^{2} 2 p^{5} 3 s^{1} ) shows the : A. ground state of the fluorine atom B. excited state of the fluorine atom c. excited state of the neon atom D. excited state of ( 0_{2}^{-} ) ion |
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| 587 | Suppose that a hypothetical atom gives a red, green, blue and violet line spectrum. Which jump according to the figure would give off the red spectral line? ( A cdot 3 rightarrow 1 ) B ( .2 rightarrow 1 ) ( c cdot 4 rightarrow 1 ) ( D cdot 3 rightarrow 2 ) |
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| 588 | Everything in the universe is made up of material called as A . life B. water c. matter D. None of the above |
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| 589 | An electron is accelerated to one-tenth the velocity of light. Suppose its velocity can be measured with a precision of ( 1 % ) what must be the uncertainty in position? A. ( 2.13 times 10^{-10} ) B . ( 1.93 times 10^{-10} ) c. ( 3.85 times 10^{-10} ) D. ( 1.52 times 10^{-10} ) |
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| 590 | Number of photons emitted in 10 hours by ( 60 mathrm{W} ) sodium lamp is ( left(lambda=5983 A^{circ}right) ) A. ( 6.40 times 10^{22} ) B. ( 6.40 times 10^{24} ) c. ( 4.60 times 10^{22} ) D. ( 4.60 times 10^{42} ) |
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| 591 | What is ratio of time periods ( left(T_{1} / T_{2}right) ) in second orbit of hydrogen atom to third orbit of ( boldsymbol{H} boldsymbol{e}^{+} ) ion? ( A cdot frac{8}{27} ) в. ( frac{32}{27} ) c. ( frac{27}{32} ) D. ( frac{27}{8} ) |
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| 592 | 44. If 2, and I are the wavelengths of the first members of the Lyman and Paschen series, respectively, then 2:2 is (a) 1:3 (b) 1:30 (c) 7:50 (d) 7:108 |
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| 593 | in the state whose multiplicity is three and the total angular 108. An atom is in the state whose multiplicity is momentum is ħv 20. What can the corresponding quan Vhat can the corresponding quantum number L be equal to? |
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| 594 | The excitation energy of first excited state of a hydrogen like atom is ( 40.8 e V ) Find the energy needed to remove the electron to form the ion. |
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| 595 | If ( 1.0 mathrm{g} ) body is traveling along the ( mathrm{x} ) -axis at ( 100 mathrm{cm} mathrm{s}^{-1} ) within error limits of ±1 ( mathrm{cm} mathrm{s}^{-1}, ) what is the uncertainty in its position? ( mathbf{A} cdot 5 times 10^{-30} mathrm{m} ) B. ( 5 times 10^{-31} mathrm{m} ) c. ( 5 times 10^{-20} mathrm{m} ) D. ( 5 times 10^{-10} mathrm{m} ) |
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| 596 | Assertion Bohr had to postulate that the electrons in stationary orbits around the nucleus do not radiate. Reason According to classical physics all moving electrons radiate. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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| 597 | According to Rutherford’s atomic model entire mass of the atom is concentrated at the A . electron B. nucleus c. proton D. none of these |
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| 598 | The position of ( ldots ldots . . . . ) could not be explained in the plum pudding model. A. nucleus B. electrons c. protons D. all of the above |
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| 599 | Electrons are particles of negligible mass carrying unit negative charge. A. True B. False |
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| 600 | The ( overrightarrow{boldsymbol{v}} ) for the first emission line of hydrogen atomic spectrum in the Balmer series with respect to the Rydberg constant ( boldsymbol{R} ) is: |
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| 601 | In the hydrogen atom spectrum ( lambda_{3-1} ) and ( lambda_{2-1} ) represent wavelengths emitted due to transition from second and first excited states to the ground state respectively. The value of ( frac{lambda_{3-1}}{lambda_{2-1}} ) is : ( mathbf{A} cdot 27 / 32 ) в. ( 32 / 27 ) c. ( 4 / 9 ) D. ( 9 / 4 ) |
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| 602 | Which of the following is a nuclear process that results in no change in the mass number and atomic number of a nuclide? A. Gamma decay B. Nuclear fusion c. Alpha decay D. Positron emission E. Nuclear fission |
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| 603 | The state ( S_{1} ) is: A . ( 1 s ) в. ( 2 s ) c. ( 2 p ) D. ( 3 s ) |
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| 604 | Q. 48 Assertion (A) All isotopes of a given element show the same chemical behaviour. Reason (R) The chemical properties of an atom are controlled by the number of electrons in the atom. (a) Both A and Rare true and R is the correct explanation of A (b) Both A and R are true but is not the correct explanation of A (c) A is true but R is false (d) Both A and Rare false |
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| 605 | The threshold energy of a metal is 10 sV Identify the incorrect option. (E = energy of one photon) A. If ( E=12 e V ), photoelectric effect occurs B. If ( E=15 e V ), kinetic energy of electron is more than option (A) C. If intensity of photon increase but energy remain same, the kinetic energy of photoelectron remain same D. If intensity of photon increase but energy remain same, the kinetic energy of photoelectron increase |
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| 606 | What is the electron configuration for manganese? A ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{5} ) B . ( [A r] 4 s^{1} ) C ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} 3 d^{5} ) D. ( 1 s^{2} 2 s^{2} 2 p^{1} ) |
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| 607 | ( C a^{2+} ) is isoelectronic with? ( mathbf{A} cdot M g^{2+} ) в. ( K r ) c. ( A r ) D. ( N a^{+} ) |
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| 608 | An element has atomic number ( 30 . ) Its cation has 2 units positive charge. How many protons and electrons are present in the cation? |
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| 609 | Complete the given balanced equation and find out the missing term. ( _{6}^{14} C rightarrow_{4}^{10} B e+? ) B . ( _{1}^{0} ) ( mathrm{c} cdot_{2}^{4} mathrm{He} ) ( D cdot_{0}^{0} ) E ( . quad begin{array}{l}n \ nend{array} ) |
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| 610 | In a certain Bohr orbit, the total energy is ( -4.9 e V . ) For this orbit, the kinetic energy, and potential energy are respectively: A. ( 9.8 e V,-4.9 e V ) в. ( 4.9 e V,-9.8 e V ) c. ( 4.9 e V,-4.9 e V ) D. ( 9.8 e V,-9.8 e V ) |
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| 611 | The wavelength associated with a golf weighing ( 200 g ) and moving at a speed of ( 5 m / h ) is of the order: B . ( 10^{-20} m ) ( mathbf{c} cdot 10^{-30} m ) D. ( 10^{-40} m ) |
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| 612 | In the pinwheel galaxy, atomic number of all elements are the same as that on earth and paulis principle is obeyed However the shell closest to the nucleus is saturated with electrons before the next shell starts to fill and the process continues this way, also each orbital can accommodate only one electron having ( +frac{1}{2} ) spin. If noble gases are defined as the elements with completely filled outermost shell, which elements would be the nobel gas in their periodic table? A ( . A r ) в. ( S i ) ( c . F ) D. Ne |
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| 613 | Decrease in atomic number is observed during: This question has multiple correct options A . ( alpha ) -emission B. ( beta ) -emission c. Positron emission D. K-capture |
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| 614 | Which one of the following constitutes a group of the isoelectronic species? A. ( mathrm{CN}^{-}, mathrm{N}_{2}, mathrm{O}_{2}^{2-}, mathrm{C}_{2}^{2-} ) в. ( mathrm{N}_{2}, mathrm{O}_{2}^{-}, mathrm{NO}^{+}, mathrm{CO} ) ( mathrm{c} cdot mathrm{C}_{2}^{2-}, mathrm{O}_{2}^{-}, mathrm{CO}, mathrm{NO} ) D. ( mathrm{NO}^{+}, mathrm{C}_{2}^{2-}, mathrm{CN}^{-}, mathrm{N}_{2} ) |
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| 615 | Rydberg constant is: A. same for all elements B. different for different elements C . a universal constant D. is different for lighter elements but same for heavier elements |
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| 616 | The alpha particles get deflected by : A. very small amounts B. very large amount c. same amount D. ( 90^{circ} ) |
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| 617 | Bohr’s atomic model is based on the following postulates that: This question has multiple correct options A. an atom consists of nucleus B. an electron can rotate only in certain energy levels C . an electron remains moving with continuous loss of energy D. None of the above |
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| 618 | A ( 0.66 k g ) ball is moving with a speed of ( 100 m / s . ) The associated wavelength will be: ( left(h=6.6 times 10^{-34} J sright) ) В. ( 6.6 times 10^{-34} m ) c. ( 1 times 10^{-35} m ) D. ( 1 times 10^{-32} ) |
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| 619 | DI LILIT 2. Which of the following is true when Bohr gave his model for hydrogen atom? (a) It was not known that hydrogen lines could be explained as differences of terms like Rin’ with R being a constant and n an integer. (b) It was not known that positive charge is concentrated in a nucleus of small size. (c) It was not known that radiant energy occurred in energy bundles defined by hv with h being a constant and va frequency. (d) Bohr knew terms like R/nand in the process of choosing allowed the orbits to fit them, he got “angular momentum = n;/21 as a deduction. |
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| 620 | The correct set of quantum numbers for the unpaired electron of a chlorine atom is: A ( cdot 2,0,0,+frac{1}{2} ) в. ( _{2,1,-1,+frac{1}{2}} ) c. ( _{3,1,1, pm} frac{1}{2} ) D. ( _{3,0,0, pm} underline{1} ) |
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| 621 | Assertion The ground state electron configuration orbitals of elemental ( boldsymbol{C u} ) is ( [boldsymbol{A} boldsymbol{r}] boldsymbol{4} boldsymbol{s}^{1} boldsymbol{3} boldsymbol{d}^{1} ) Reason Completely half-filled and filled dorbital best show special electronic stabilization A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 622 | Which value of ( n ) and ( k ) suggests about the shape of 3s orbital? ( A cdot 3,2 ) в. 1,1 ( c cdot 3,0 ) D. 3,3 |
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| 623 | Which transition in ( L i^{2+} ) would have the same wavelength as the ( 2 rightarrow 4 ) transition in ( boldsymbol{H} boldsymbol{e}^{+} ) ion? ( A cdot 4 ) to 6 B. 4 to 3 ( c cdot 5 ) to 6 D. 5 to 4 |
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| 624 | A radioactive nuclide emits ( gamma ) -rays due to: A ( . K ) -electron capture B. nuclear transition from higher to lower energy state C. presence of greater number of neutrons than protons D. presence of greater number of protons than neutrons |
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| 625 | A hydrogen-like atom in ground state absorbs n photons having the same energy and its emits exactly n photons when electrons transition takes placed. Then, the energy of the absorbed photon may be : This question has multiple correct options A. 91.8 eV в. 40.8 eV c. 48.4 eV D. 54.4 eV |
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| 626 | Oil ( A ) is at ( 300^{circ} ) C whereas oil ( B ) is at ( 530^{circ} ) F. Which one is hotter? A. ( A ) в. ( B ) c. Both are same D. Can not be predicted |
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| 627 | 68. The wavelength of radiation required to excite the electron from the first orbit to the third orbit in a doubly ionized lithium atom will be (a) 134.25 Å (c) 125.5 Å (c) 113.7 Å (d) 110 Å |
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| 628 | The mass of proton is ( _{—}– ) times the mass of an electron. A . 1822 в. 1857 ( c cdot 1869 ) D. 1837 |
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| 629 | Which of the following constitutes a group of isoelectronic species? A ( cdot C O, N_{2}, O_{2}^{-} ) в. ( N_{2}, C N^{-}, N O^{+} ) ( mathrm{c} cdot O_{2}^{-}, N O, C_{2}^{2} ) D. ( C l^{-}, A r, N A^{+} ) E ( cdot S^{2-}, C a^{2+}, C N^{-} ) |
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| 630 | The velocity of all electromagnetic radiation is ( x times 10^{8} mathrm{m} mathrm{s}^{-1} ) Value of ( x ) is : |
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| 631 | A beam of helium atoms moves with a velocity of ( 2 times 10^{4} . ) Find the wavelength of particles constituting with the beam |
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| 632 | Assertion In an atom, the velocity of electrons in the higher orbits keeps on decreasing. Reason Velocity of electron in an orbit is inversely proportional to the radius of the orbit. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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| 633 | Assertion The angular momentum of an electron in an atom is quantized. Reason In an atom only those orbits are permitted in which angular momentum of the electron is integral multiple of ( frac{h}{2 pi} ) where ( h ) is a plank’s constant. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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| 634 | Match the items in List 1 with those in List 2 |
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| 635 | “Electrons can jump from one orbit to other orbit. They cannot flow from one orbit to another” Justify. |
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| 636 | The fundamental particles present in equal numbers in neutral atoms (atomic number ( 71) ) are A. protons and electrons B. neutrons and electrons c. protons and neutrons D. protons and positrons |
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| 637 | There is a transition from ( n=1 ) to ( n=2 ) and then ( n=2 ) to ( n=3, ) then: A. ( Delta E ) values as well as frequency are additive B. wave length as well as frequency are additive c. ( Delta E ) values as well as wavelength are additive D. all of the parameters, ( (Delta E, ) frequency and wave length are additive |
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| 638 | An f-shell containing 6 unpaired electrons can exchange: A. 6 electrons B. 9 electrons c. 12 electrons D. 15 electrons |
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| 639 | The total energy of the electron of ( boldsymbol{H} ) atom in the second quantum state is ( -boldsymbol{E}_{2} . ) The total energy of the ( boldsymbol{H} boldsymbol{e}^{+} ) atom in the third quantum state is: ( ^{mathrm{A}} cdot-left(frac{3}{2}right) E_{2} ) в. ( -left(frac{2}{3}right) E_{2} ) c. ( -left(frac{4}{9}right) E_{2} ) D. ( -left(frac{16}{9}right) E_{2} ) |
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| 640 | Atoms of different elements having the same mass number are known as: A. isotopes B. isobars c. isotones D. isomers |
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| 641 | The wavelength photon obtained by electron transition between two level in H-atom and singly ionised ( boldsymbol{H} e ) are ( boldsymbol{lambda}_{mathbf{1}} ) and ( lambda_{2} ) respectively, then: A ( cdot lambda_{2}=lambda_{1} ) B ( cdot lambda_{2}=2 lambda_{1} ) c. ( lambda_{2}=lambda_{1} / 2 ) D. ( lambda_{2}=lambda_{1} / 4 ) |
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| 642 | If Atom 1 has 19 protons and 22 neutrons and Atom 2 has 20 protons and 22 neutrons, are these isotopes of the same element? A. There is not enough information to determine this. B. No, because they have different numbers of protons. c. No, because they have the same number of neutrons. D. Yes, because they have different numbers of protons E. Yes, because they have the same number of neutrons |
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| 643 | Which quantum number is not related with Schrodinger equation? A. Principal B. Azimuthal c. Magnetic D. spin |
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| 644 | Relative molecular mass is the ratio of A. the average mass of one molecule of an element or compound to of the mass of an atom of carbon-12 B. the average mass of one molecule of an element or compound to one twelfth of the mass of an atom of carbon-12 C. the average mass of one molecule of an element or compound to one fifth of the mass of an atom of carbon-12 D. the average mass of one molecule of an element or compound to one twelfth of the mass of an atom of carbon-16 |
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| 645 | PICUOU COU L OI – – – Q27. Give the number of electrons in the species : ,,H, and 0,*. Ang L+ ana + – 15 |
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| 646 | The energy of a hydrogen atom in the ground state is ( 13.6 mathrm{eV} ). The energy of a ( mathrm{He}^{+} ) ion in the first excited state will be: A . -6.8 ev B . -13.6 ev c. – 27.2 ev D. – 54.4 ev |
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| 647 | Which one contains up to ten electrons from the following? A . ( 1 s ) B . ( 2 s ) ( c cdot 3 s ) D. ( 3 p ) E . ( 3 d ) |
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| 648 | C-14 has a half life of A. 11520 yrs B. 2880 yrs c. 5760 yrs D. 17280 yrs |
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| 649 | Anode rays are also called as: A. Cathode Rays B. Canal Rays c. ( x ) -rays D. None of these |
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| 650 | From the electronic configuration of the given elements ( boldsymbol{K}, boldsymbol{L}, boldsymbol{M} ) and ( boldsymbol{N}, ) which one has the highest ionization potential? ( mathbf{A} cdot M=[N e] 3 s^{2} 3 p^{2} ) B . ( L=[N e] 3 s^{2} 3 p^{3} ) C ( cdot K=[N e] 3 s^{2} 3 p^{1} ) D cdot ( N=[A r] 3 d^{10}, 4 s^{2} 4 p^{3} ) |
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| 651 | 6. The angular momentum of an electron in an orbit is quantized because it is a necessary condition for the compatibility with (a) wave nature of electron (b) particle nature of electron (c) Pauli’s exclusion behavior (d) none of these |
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| 652 | Which statements concerning Bohr’s model are true? This question has multiple correct options A. Predicts that probability of electron near nucleus is more B. Angular momentum of electron in H-atom ( =frac{n h}{2 pi} ) C. Introduces the idea of stationary states D. Explain line spectrum of hydrogen |
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| 653 | The frequency of resulting spectral line, in cycle per seconds is: A. ( 1.93 times 10^{-11} ) В. ( 2.9 times 10^{16} ) c. ( 1.93 times 10^{11} ) D. ( 2.9 times 10^{-11} ) |
11 |
| 654 | d) = NUW 26. If a surface has work function of 3.00 eV, the longest wavelength of light which will cause the emission of electrons is (a) 4.8 x 10-7 m (b) 5.99 x 10-7 m (C) 4.13 x 10-7 m (d) 6.84 x 10-7 m |
11 |
| 655 | The wavelength of light emitted by electron in ( C^{5+} ) ion during transition from ( n=3 ) to ( n=1 ) is approximately: A. 2.85 nm B. 3.6 пт ( c .8 .7 n m ) D. ( 9.8 n m ) |
11 |
| 656 | The number of electrons in ( 3 d ) orbitals for element with Atomic number 26 is: A . 4 B. 6 ( c cdot 8 ) D. 10 |
11 |
| 657 | The Balmer series of hydrogen spectra lies in: A. visible region spectra B. ultra violet spectra c. infrared region spectra D. ( gamma ) -rays spectra |
11 |
| 658 | Which orbital is represented by wave function ( Psi_{310} ? ) A ( cdot 3 d_{x y} ) B . ( 3 p_{z} ) ( c cdot 4 s ) D. ( 4 d_{z} ) |
11 |
| 659 | cu CSULT 4. The idea of stationary orbits was first given by (a) Rutherford (b) JJ. Thomson (C) Niels Bohr (d) Max Planck |
11 |
| 660 | The wavelength of ( beta ) -line of the Balmer series is ( 4815 A ). What is the wavelength of ( alpha ) -line of the Balmer series of the same atom? |
11 |
| 661 | The Schrodinger wave equation is based on which nature of electron? A. wave B. Particle c. atomic D. Both A and E |
11 |
| 662 | The spectral lines corresponding to the radiation emitted by an electron jumping from 6 th, 5 th and 4 th orbits to second orbit belong to: A. Lyman series B. Balmer series c. Paschen series D. Pfund series |
11 |
| 663 | The principal quantum number and azimuthal quantum number values for the differentiating electron of ‘d’ block elements are and |
11 |
| 664 | The isoelectronic pair is: A. ( C l_{2} O, I C l_{2} ) в. ( C l_{2}, C l O_{3}^{-} ) ( mathbf{c} cdot I F_{2}^{+}, I_{3}^{-} ) D. ( C l O_{2}^{-}, C l F_{2} ) |
11 |
| 665 | A metal was irradiated by light of frequency ( 3.2 times 10^{15} s^{-1} . ) The photoelectron produced had its ( mathrm{KE}, 2 ) times the KE of the photoelectron which was produced when the same metal was irradiated with a light of frequency ( 2.0 times 10^{15} s^{-1} . ) What is the ionization energy of metal? |
11 |
| 666 | The atomic masses of ( H e ) and ( N e ) are 4 and 20 amu, respectively. The value of the de Broglie wavelength of ( H e ) gas at ( -73^{0} C ) is ( ” M^{prime prime} ) times that of the de Broglie wavelength of ( N e ) at ( 727^{0} C . M ) is: ( mathbf{A} cdot mathbf{5} ) B. 0.2 ( c cdot 2 ) D. 0.5 |
11 |
| 667 | Calculate the wavelength of radiation emitted producing a line in Lyman series, when an electron falls from fourth stationary state in hydrogen ( operatorname{atom}left(boldsymbol{R}_{boldsymbol{H}}=mathbf{1 . 1} times mathbf{1 0}^{mathbf{7}} boldsymbol{m}^{-mathbf{1}}right) . ) If the answer is ( x times 10^{-8} mathrm{m} ), then find the value of ( x ) |
11 |
| 668 | Q. 21 Which of the following statements concerning the quantum numbers are correct? (a) Angular quantum number determines the three dimensional shape of the orbital (b) The principal quantum number determines the orientation and energy of the orbital (c) Magnetic quantum number determines the size of the orbital (d) Spin quantum number of an electron determines the orientation of the spin of electron relative to the chosen axis |
11 |
| 669 | State True or False. ( mathrm{Fe}^{3+} ) is paramagnetic. A. True B. False |
11 |
| 670 | The electronic configuration of gadolinium (Atomic No.64) is: ( mathbf{A} cdot[X e] 4 f^{3} 5 d^{5} 6 s^{2} ) ( mathbf{B} cdot[X e] 4 f^{6} 5 d^{2} 6 d^{2} ) ( mathbf{c} cdot[X e] 4 f^{8} 5 d^{9} 6 s^{2} ) ( mathbf{D} cdot[X e] 4 f^{7} 5 d^{1} 6 s^{2} ) |
11 |
| 671 | Q. 2 Which of the following options does not represent ground state electronic configuration of an atom? (a) 1s 2s 2p 3s 3p 3 do 4 00 (b) 1s 2s 2p 3s 3p3.dº45 (c) 1s²2s22p 3s 3p%3d045! (d) 1s 2s 2p 3s 3p 3d 4s! |
11 |
| 672 | Mark the incorrect relation. A ( cdot N_{0}=N E^{lambda t} ) B . ( tau=1.44 t_{0.5} ) ( ^{mathrm{c}} N=N_{0}left(frac{1}{2}right)^{n} ) D. ( t_{1 / 2}=2.303 lambda log 2 ) |
11 |
| 673 | Assertion The magnetic moment of ( M g ) -atom is more than ( K ) -atom as the former has two electrons in outermost shell. Reason The magnetic moment of ( N ) -atom is more than magnetic moment of ( O ) -atom and former has more number of unpaired electrons. A. Assertion is correct but Reason is wrong. B. Assertion is wrong but Reason is correct. c. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion. D. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion. |
11 |
| 674 | The Bohr radius for the hydrogen atom ( boldsymbol{n}=mathbf{1}) ) is approx ( mathbf{0 . 5 3} boldsymbol{A}^{o} . ) The radius for the first excited state ( (n=2 ) orbit) is ( left(operatorname{in} A^{o}right) ) A . 0.13 B. 1.06 c. 4.77 D. 2.12 |
11 |
| 675 | PDT 5) 4. Using Aufbau principle, write the ground state electronic configuration of following atoms, (i) Boron (Z = 5) (ii) Neon (Z = 10), (iii) Aluminium (Z = 13) (iv) Chlorine (Z = 17), (v) Calcium (Z = 20) (vi) Rubidium (Z = 37) 12.2.1 |
11 |
| 676 | The atomic weight of an element is 23 and its atomic number is ( 11 . ) The number of proton, electrons and neutrons respectively, present in the atom of the element are A. 11,11,12 В. 12,12,11 c. 11,12,11 D. 12,11,12 |
11 |
| 677 | ( boldsymbol{H} ) -atoms in ground state ( (mathbf{1 3 . 6 e V}) ) are excited by monochromatic radiations of photon of energy ( 12.1 e V ). The number of spectral lines emitted in ( boldsymbol{H} ) -atom will be: A . 1 B. 2 ( c .3 ) D. 6 |
11 |
| 678 | The radius of the shortest orbit in a one- electron system is 18 pm. It may be A. hydrogen B. deuterium ( mathrm{c} cdot H^{+} ) D. ( L^{++} ) |
11 |
| 679 | Mass number is A. the sum of the total number of protons and neutrons present in the nucleus of an atom. B. the electrons present in the outermost shell of an atom. C. an atom of each element having a definite combining capacity. D. the total number of protons present in the nucleus of an atom. |
11 |
| 680 | We can say that the energy of frequency ( boldsymbol{v} ) is given by ( boldsymbol{E}=boldsymbol{h} boldsymbol{v}, ) where ( boldsymbol{h} ) is Planck’s constant. The momentum of a photon is ( p=frac{h}{lambda} ) where ( lambda ) is the wavelength of photon. Then we may conclude that velocity of light is equal to: A ( cdotleft(frac{E}{P}right)^{1 / 2} ) в. c. Ep D. ( left(frac{E}{P}right)^{2} ) |
11 |
| 681 | Assertion ( P ) orbital is dumb-bell shaped. Reason Electron present in p orbital can have any one of the three values of the magnetic quantum number, i.e 0,+1 or -1 Read the above assertion and reason and choose the correct option regarding ¡t. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 682 | Rutherford’s atomic model could not explain the stability of atom. How do you account for this? |
11 |
| 683 | Formula of Heisenberg uncertainty principle is: |
11 |
| 684 | The uncertainty (in meters) in the position of an insect weighing ( 0.68 g ) and traveling at a velocity of ( 0.85 mathrm{m} / mathrm{s} ) (the uncertainty in the velocity is 0.1 ( m / s), ) is: A. ( 8 times 10^{-21} mathrm{m} ) В. ( 4 times 10^{-25} mathrm{m} ) c. ( 8 times 10^{-31} m ) D. ( 8 times 10^{-34} m ) |
11 |
| 685 | According to Bohr theory, the electronic energy of hydrogen atom in the ( n ) th Bohr orbit is given by, [ boldsymbol{E}_{boldsymbol{n}}=-frac{boldsymbol{2} mathbf{1} . boldsymbol{7} boldsymbol{6} times mathbf{1 0}^{-19}}{boldsymbol{n}^{2}} boldsymbol{J} ] Calculate the longest wavelength of light that will be needed to remove an electron from the 2 nd orbit of ( L i^{2+} ) ion. |
11 |
| 686 | Q2. Define atomic number, mass number and neutron. How are the three related to each other? Ana Alami Membaw (). The atomic numher of an element is equal to the number of |
11 |
| 687 | What led to the failure of Dalton’s atomic theory? A. Discovery of fundamental particle electron inside the atom B. Discovery of fundamental particle proton inside the atom c. Discovery of canal rays D. Both A and B |
11 |
| 688 | The force which is responsible for circular motion of electrons around the nucleus is A. Van der Waals B. Electrostatic forces c. centrifugal and Centripetal D. Intermolecular forces |
11 |
| 689 | Which of the following was not proposed by Thomson? A. The negative and positive charges are equal in magnitude B. The electrons revolve around the nucleus in circular paths C. The electrons are embedded in a positive sphere D. Atoms are electrically neutral |
11 |
| 690 | Atoms with same atomic number and different mass numbers are called: A. Isobars B. Isomers c. Isotones D. Isotopes |
11 |
| 691 | Total no of lines in Lyman series of ( mathrm{H} ) spectrum will be (where ( n= ) no.of orbits) ( A cdot n ) B. ( n(n-1) / 2 ) ( c cdot n-2 ) ( D cdot n(n+1) ) |
11 |
| 692 | Which of the following sets of quantum numbers is correct for an electron in ( 4 f ) orbital? A ( . n=4, l=3, m=+4, s=+1 / 2 ) в. ( n=4, l=4, m=-4, s=-1 / 2 ) c. ( n=4, l=3, m=+1, s=+1 / 2 ) |
11 |
| 693 | A naturally occuring sample of copper consists of ( 69.2 % ) of ( ^{63} mathrm{Cu} ) and ( 30.8 % ) of ( ^{65} mathrm{Cu} . ) The relative mass of ( ^{63} mathrm{Cu} ) is 62.93 and that of ( ^{65} mathrm{Cu} ) is ( 64.93 . ) Find the atomic mass of a naturally occuring sample of copper. A. 64.348 B. 63.546 c. 64.12 D. none of these |
11 |
| 694 | Which of the following is the correct form of Schrodinger wave equation? A ( cdot frac{partial^{2} Psi}{partial^{2} x}+frac{partial^{2} Psi}{partial^{2} y}+frac{partial^{2} Psi}{partial^{2} z}+frac{8 pi^{2} m}{h^{2}}(E-V) Psi=0 ) B ( cdot frac{partial^{2} Psi}{partial x^{2}}+frac{partial^{2} Psi}{partial y^{2}}+frac{partial^{2} Psi}{partial z^{2}}+frac{8 pi^{2} m}{h^{2}}(E-V) Psi=0 ) C ( cdot frac{partial Psi^{2}}{partial x^{2}}+frac{partial Psi^{2}}{partial y^{2}}+frac{partial Psi^{2}}{partial z^{2}}+frac{8 pi^{2} m}{h^{2}}(E-V) Psi=0 ) D ( cdot frac{partial^{2} Psi}{partial x^{2}}+frac{partial^{2} Psi}{partial y^{2}}+frac{partial^{2} Psi}{partial z^{2}}+frac{8 pi^{2} m^{2}}{h^{2}}(E-V) Psi=0 ) |
11 |
| 695 | Assuming ( z- ) axis inter nuclear axis. In which of the following orbitals overlap to form ( sigma ) bond ( boldsymbol{s}+boldsymbol{p}_{boldsymbol{x}} ) |
11 |
| 696 | The uncertainty in momentum of a particle is ( 3.31 times 10^{-2} mathrm{Kg} ) msec ( ^{-1} ) Calculate uncertainty in its position. A. ( 6.4 times 10^{-33} m ) m В. ( 1.6 times 10^{-33} m ) c. ( 3.2 times 10^{-33} m ) D. ( 5 times 10^{-33} m ) E ( .2 .5 times 10^{-33} m ) |
11 |
| 697 | The value of ( e / m ) of an electron was measured by : A. Millikan B. J.J. Thomson c. Dalton D. Rutherford |
11 |
| 698 | Which of the following is responsible to rule out the existance of defence of definite paths or trajectories of electrons? A. Pauli’s exclusion principle B. Heisenberg’s uncertainty principle c. Hund’s rule of maximum multiplicity D. Aufbau principle |
11 |
| 699 | 9. If the series limit of Lymen series for Hydrogen atom is equal to the series limit of Balmer series for a hydrogen like atom, then atomic number of this hydrogen-like atom will be (a) 1 (b) 2 (c) 3 (d) 4 |
11 |
| 700 | is the nuclear process that transmutes uranium-238 into thorium-234. A. Gamma decay B. Nuclear fusion c. Alpha decay D. Positron emission E. Nuclear fission |
11 |
| 701 | An atom has ( x ) energy level, then total number lines in its spectrum are? A ( .1+2+3 ldots .(x+1) ) B. ( 1+2+3 ldotsleft(x^{2}right) ) c. ( 1+2+3 ldots .(x-1) ) D. ( (x+1)(x+2)(x+4) ) |
11 |
| 702 | On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements. | 11 |
| 703 | It was found that electrons have negligible mass but have one unit of negative charge. Which of the following model satisfies this statement?? A. Thomson’s atomic model B. Goldstein’s atomic model c. chadwick’s atomic model D. None of the above |
11 |
| 704 | Which of the following has negative charge and pairs with opposite spin? A. Proton B. Neutron c. Electron D. Isotope E. lon |
11 |
| 705 | An electron in an atom undergoes transition in such a way that its kinetic energy changes from ( x ) to ( frac{x}{4}, ) the change in potential energy will be: A ( cdot+frac{3}{2} x ) B. ( -frac{3}{8} x ) ( c cdot+frac{3}{4} x ) D. ( -frac{3}{4} x ) |
11 |
| 706 | Which is characteristic of unstable nucleus? This question has multiple correct options ( mathbf{A} cdot n / p ) ratio is high B. Low binding energy C. High packing fraction D. None of these |
11 |
| 707 | For the given orbital in Column I, the only CORRECT combination for any hydrogen-like species is ( A cdot(1 vee) ) (iv) B. (III) (iii) (P) ( c .(11) ) (ii) (P) D. (I) (ii) (S) |
11 |
| 708 | Assertion Kinetic energy of photoelectrons increases with increase in the frequency of incident radiation. Reason The number of photoelectrons ejected increases with increase in intensity of incident radiation. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
11 |
| 709 | A golf ball has a mass of 40 g, and a speed of ( 45 mathrm{m} / mathrm{s}, ) if speed can be measured within accuracy of ( 2 % ) calculate the uncertainty in the position. A . ( 1.56 times 10^{-30} ) В. ( 1.46 times 10^{-33} mathrm{m} ) c. ( 1.47 times 10^{-23} mathrm{m} ) D. ( 1.47 times 10^{-30} mathrm{m} ) |
11 |
| 710 | The isotope of hydrogen which is/are radioactive in nature: A. protium and deuterium B. tritium and deuterium c. only tritium D. only deuterium |
11 |
| 711 | If principal quantum number ( n=5, ) then the total number of orbitals present in a given stationary state is: A .24 B. 25 ( c cdot 26 ) D. 27 |
11 |
| 712 | A photon of wavelength ( 4400 dot{A} ) is passing through vacuum. The effective mass and momentum of the photon are respectively? A ( .5 times 10^{-36} k g, 1.5 times 10^{-27} k g-m / s ) B . ( 5 times 10^{-25} mathrm{kg}^{text {‘ }}, 1.5 times 10^{-26} mathrm{kg}-mathrm{m} / mathrm{s} ) C. Zero, ( 1.5 times 10^{-26} mathrm{kg}-mathrm{m} / mathrm{s} ) D. ( 5 times 10^{-36} ) в ( g ), ( 1.36 times 10^{-43} ) kg ( -m / s ) |
11 |
| 713 | Radius of the nucleus is about times less than the radius of the atom. A ( cdot 10^{3} ) B. ( 10^{text {। }} ) ( c cdot 10^{5} ) D. ( 10^{2} ) |
11 |
| 714 | In the degenerate orbitals, unpaired electrons have same spin. A. True B. False |
11 |
| 715 | 5. The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy? I (a) II (c) IV (d) III II I TYN=1 (b) I (AIEEE 2005) |
11 |
| 716 | The orbital angular momentum of an electron corresponding to ( n=4 ) and ( boldsymbol{m}=-mathbf{3} ) is: A . 0 в. ( frac{h}{sqrt{2} pi} ) c. ( frac{sqrt{6} h}{2 pi} ) D. ( frac{sqrt{3} h}{pi} ) |
11 |
| 717 | Define Aufbau Principle | 11 |
| 718 | In an atom two electrons move around the nucleus in circular orbits of radii and ( 4 mathrm{R} ). The ratio of the time taken by them to complete one revolution is: A .1: 4 B . 4: 1 c. 1: 8 D. 8: 7 |
11 |
| 719 | The number of unpaired electrons in a chromic ion ( left.C r^{3+} text { (atomic number } 24right) ) is: ( A cdot 6 ) B. 4 ( c .3 ) D. |
11 |
| 720 | ULIWA Q1. (a) What is the limitations of Rutherford model of atoms? (b) How has Bohr’s theory helped in calculating the energy of hydrogen electron in different energy levels? |
11 |
| 721 | Which one of the following sets of ions represents a collection of isoelectronics species? A. ( K^{+}, C l^{-}, C a^{2+} ) B. ( B a^{2+}, S r^{2+}, K^{+}, C a^{2+} ) c. ( N^{3}-, O^{2-}, C a^{2+}, S^{2} ) D. ( L i^{+}, N a^{+}, M g^{2+}, C a^{2+} ) |
11 |
| 722 | A formula analogous to the Rydberg formula applies to the series of spectral lines which arise from transitions from higher energy level to the lower energy level of hydrogen atom. A muonic hydrogen atom is like a hydrogen atom in which the electron is replaced by a heavier particle, the muon’. The mass of the muon is about 207 times the mass of an electron, while the charge remains same as that of the electron. Rydberg formula for hydrogen atom is: ( frac{1}{lambda}= ) ( boldsymbol{R}_{boldsymbol{H}}left[frac{mathbf{1}}{boldsymbol{n}_{mathbf{1}}^{2}}-frac{mathbf{1}}{boldsymbol{n}_{2}^{2}}right]left(boldsymbol{R}_{boldsymbol{H}}=mathbf{1 0 9 6 7 8 c m}^{-1}right) ) Radius of first Bohr orbit of muonic hydrogen atom is A ( cdot frac{0.259}{207} dot{A} ) B. ( frac{0.529}{207} ), c. ( 0.529 times 207 hat{A} ) D. ( 0.259 times 207 dot{A} ) |
11 |
| 723 | Which of the following can occupy space and has mass? A. Density B. weight c. Matter D. A solid E. volume |
11 |
| 724 | Most of the alpha particles pass: A. straight through the gold foil B. unusual through the gold foil C . rare through the gold foil D. none of the above |
11 |
| 725 | Isotopes have same A. atomic mass number B. atomic number C. number of neutrons D. moles |
11 |
| 726 | Find the ratio of specific charges ( left(frac{boldsymbol{q}}{boldsymbol{m}}right) ) of an ( alpha- ) particle and a deuteron? | 11 |
| 727 | ( N a^{+}, M g^{2+}, A l^{3+} ) and ( S i^{4+} ) are isoelectronic ions. Their ionic size follows the order: A ( cdot N a^{+}<M g^{2+}<A l^{3+} C. ( N a^{+}A l^{3+}>S i^{4+} ) D. ( N a^{+}>M g^{2+}>A l^{3+}>S i^{4+} ) |
11 |
| 728 | Although ( C N^{-} ) ion and ( N_{2} ) molecule are isoelectronic, yet ( N_{2} ) molecule is chemically inert because of: A. presence of more number of electrons in bonding orbitals B. a bond energy c. absence of bond polarity D. uneven electron distribution |
11 |
| 729 | An ion ( M^{2+} ) contains 10 electrons and 12 neutrons. What is the atomic number and mass number of element M? A .10,24 B. 10,22 c. 12,24 D. 12, 22 |
11 |
| 730 | Which of the following element is represented by electronic configuration ( mathbf{1} boldsymbol{s}^{2} mathbf{2} boldsymbol{s}^{2} mathbf{2} boldsymbol{p}_{boldsymbol{x}}^{1} mathbf{2} boldsymbol{p}_{boldsymbol{y}}^{mathbf{1}} boldsymbol{2} boldsymbol{p}_{z}^{1} ) A. Nitrogen B. Oxygen c. Fluorine D. sulphur |
11 |
| 731 | Which of the following atoms and ions are iso electronic(i.e have the same number of electrons) with a neon atom: ( mathbf{C}, mathbf{O}^{2-}, mathbf{N}^{-}, mathbf{F}^{+}, mathbf{N a}^{+}, mathbf{A} mathbf{l}^{mathbf{3}+} ) A ( cdot mathrm{N}^{-}, mathrm{Na}^{+}, mathrm{Al}^{3+} ) B. ( c, O^{2}-, N a^{+}, F^{+} ) ( mathbf{c} cdot mathbf{0}^{2-}, mathbf{N a}^{+},left.mathbf{A}right|^{3} ) D. ( c, 0^{2}-, F^{+},left.Aright|^{3+} ) |
11 |
| 732 | Matter can be defined as something that: A. Occupies space B. Has mass c. Exists in three states D. All of the above |
11 |
| 733 | A quantity of aluminium has a mass of 54g. What is the mass of same number of magnesium atoms? A. ( 12.1 g ) в. ( 24.3 g ) c. ( 48.6 g ) D. ( 97.2 g ) |
11 |
| 734 | If two subshells have equal value of ( (n+1) ) and one of them has ( n=4, l=3, ) while second subshell has dumbbellshape. Then which of the bfollowing statement is/are correct? This question has multiple correct options A. Second subshell has value of ( n=6 ) B. One of the orbitals of second subshell has one nodal plane c. second subshell is d-subshell. D. First subshell is f-subshell |
11 |
| 735 | What is the maximum number of orbitals that can be identified with the following quantum numbers? ( left[n=3 ; l=1 ; m_{l}=0right] ) ( A ) B. 2 ( c cdot 3 ) D. |
11 |
| 736 | Which radioactive series do not show the formation of radon atom as one of the intermediate? A. ( T h ) series B. Np series c. ( U ) series D. ( A c ) series |
11 |
| 737 | How many elements are possible for the ( 1^{s t} ) period of periodic table if azimuthal quantum number can have integral values from 0 to ( (n+1) .[n= ) shell number and other rules are remaining same to form period table? A . 4 B. 6 ( c cdot 2 ) ( D cdot 8 ) |
11 |
| 738 | Uncertainty in the position of an electron ( left(text {mass}=mathbf{9 . 1} times mathbf{1 0}^{-mathbf{3 1}} mathbf{k g}right) ) moving with a velocity ( 300 m s^{-1} ) accurate upon ( 0.001 % ) will be: ( left[boldsymbol{h}=mathbf{6 . 6 3} times mathbf{1 0}^{-mathbf{3 4}} boldsymbol{J}-boldsymbol{s}right] ) A ( cdot 19.2 times 10^{-2} mathrm{m} ) в. ( 5.76 times 10^{-2} ) т c. ( 1.92 times 10^{-2} mathrm{m} ) D. ( 3.84 times 10^{-2} mathrm{m} ) |
11 |
| 739 | 5. Angular momentum (L) and radius (r) of a hydrogen atom are related as (a) Lr = constant (b) Lr2 = constant (c) Lrt = constant (d) none of these |
11 |
| 740 | A mixture is made from different substances that are A. not chemically joint B. chemically joint c. physically joint D. not physically joint |
11 |
| 741 | The velocity of the electron in 3rd orbit of hydrogen atom in ( mathrm{cm} s^{-1} ) A ( cdot 4.88 times 10^{4} ) B . ( 2.44 times 10^{8} ) c. ( 7.29 times 10^{7} ) D. ( 2.44 times 10^{12} ) |
11 |
| 742 | According to postulated of Bohr’s atomic model, the electron has a definite amount of energy and the electron does not lose or gain energy while moving: A. in the orbit B. in the nucleus c. in the atom D. in the molecul |
11 |
| 743 | Which one of the following represents the correct ratio of the energy, of electron in ground state of H atom to that of the electron in the first excited state of ( boldsymbol{L} boldsymbol{i}^{+} ? ) A .4: 9 B. 9: 4 ( c cdot 1: 4 ) ( D cdot 4: 1 ) |
11 |
| 744 | Ground state electronic configuration of nitrogen atom can be represented by : This question has multiple correct options ( A ) ( uparrow downarrow ) в. ( uparrow downarrow ) ( c ) ( uparrow downarrow ) ( uparrow quad downarrow quad downarrow ) D. ( uparrow downarrow ) ( downarrow downarrow downarrow downarrow downarrow ) |
11 |
| 745 | Which of the following ion is not isoelectronic with ( O^{-2} ) ? A ( cdot N^{-3} ) В. ( N a^{+} ) ( c cdot F^{-} ) D. ( T i^{+3} ) |
11 |
| 746 | (a) Calculate the radii of the first three Bohr orbits for hydrogen. (Planck’s constant ( boldsymbol{h}=mathbf{6 . 6 2 6 2} times mathbf{1 0}^{-mathbf{3 4}} ) Js; mass of electron ( boldsymbol{m}=mathbf{9 . 1 0 9 1} times ) ( 10^{-31} mathrm{kg} ; ) charge on electron ( e= ) ( mathbf{1 . 6 0 2 1 0} times mathbf{1 0}^{-mathbf{1 9}} mathbf{C} ; ) permittivity of vacuum ( epsilon_{0}=8.854185 times ) ( left.10^{-12} C^{2} N^{-1} m^{-2} .right) ) (b) Use these radii to calculate the velocity of an electron in each of these three orbits. |
11 |
| 747 | Which of the following is the standard for atomic mass? A ( cdot frac{1}{1} H ) B . ( _{6}^{12} mathrm{C} ) ( mathbf{c} cdot frac{i 4}{6} C ) D. ( _{8}^{6} C ) |
11 |
| 748 | Find Kinetic energy of an ( alpha ) -particle? ( left.boldsymbol{v}=mathbf{3} times mathbf{1 0}^{7}right) ) ( mathbf{A} cdot 1.3 times 10^{-5} ) erg В ( cdot 2.9 times 10^{-5} ) erg c. ( 8.0 times 10^{18} ) erg D. ( 8 times 10^{-18} ) erg |
11 |
| 749 | On the basis of Rutherford’s model of an atom, which subatomic particle is present it the nucleus of an atom? |
11 |
| 750 | Carbon has six protons and six neutrons in its nucleus. What is the atomic mass of carbon? ( A cdot 4 ) B. 12 ( c cdot 8 ) D. 6 |
11 |
| 751 | Which of the following isoelectronic ions have lowest ionisation energy? A . ( K^{+} ) в. ( C a^{2} ) c. ( C l^{-} ) ( D cdot S^{2} ) |
11 |
| 752 | Select the incorrect option regarding following plot. A. Minimum possible angular node will be zero B. It is for ( n-1-1=0 ) c. wave function does not depend on angle ( theta ) and ( phi ) D. It gives probability of finding the electron at a point at distance r from the nucleus |
11 |
| 753 | Which form of energy is a measure of the electron stability when it is in bound state with nucleus? A. Potential energy B. Kinetic energy c. vibrational energy D. lonization energy |
11 |
| 754 | What does the electronic configuration ( 1 s^{2}, 2 s^{2}, 2 p^{5}, 3 s^{1} ) indicate? A. Ground state of fluorine B. Excited state of fluorine c. Excited state of neon D. Excited state of the ( O_{2}^{-} ) ion |
11 |
| 755 | The maximum number of electrons in a shell with the principal quantum number ( =4 ) is : A .2 B. 10 c. 16 D. 32 |
11 |
| 756 | A microscope using suitable photons is employed to locate an electron in an atom within a distance of 0.1 A. What is the uncertainty involved in the measurement of its velocity? ( (h=6.626 ) ( times 10^{-34} mathrm{Js}, ) mass of electron ( =9.1 ) ( times 10^{-31} mathrm{kg} ) |
11 |
| 757 | 78. An electron is in an excited state in a hydrogen like atom It has a total energy of -3.4 eV. The kinetic enerov electron is E and its de Broglie wavelength is 2 (a) E= 6.8 eV; 2 = 6.6 x 10-10 m (b) E = 3.4 eV; 2 = 6.6 x 10-10 m (C) E=3.4 eV; 2 = 6.6 x 10 m (d) E = 6.8 eV; 2= 6.6 x 10 m |
11 |
| 758 | have equal number of neutrons. A. Isobars B. Isotones c. Isotopes D. Mass Number |
11 |
| 759 | If 8.0 g of radioactive isotope has a half life of 10 hours, the half life of 2.0 g of the same substance is : A. 2.5 hours B. 5.0 hours c. 10 hours D. 40 hours |
11 |
| 760 | Electromagnetic radiation having ( lambda= ) ( 310 dot{A} ) is subjected to a metal sheet having work function ( =12.8 mathrm{eV} . ) What will be the velocity of photo electrons having maximum kinetic energy? A ( cdot 1.23 times 10^{6} m / s ) B . ( 2.28 times 10^{6} mathrm{m} / mathrm{s} ) c. ( 3.1 times 10^{6} m / s ) D. None of these |
11 |
| 761 | Neutrons are discovered by: A. J.J. Thomson B. Goldstein C. Crookes D. Chadwick |
11 |
| 762 | Assertion Transition of electron between ( boldsymbol{p}_{boldsymbol{x}} ) and ( boldsymbol{p}_{boldsymbol{y}} ) would not lead to an spectral line. Reason ( p ) -orbitals are degenerate orbitals. Read the above assertion and reason and choose the correct option regarding ¡t. A. Both Assertion and Reason are correct and the Reason is the correct explanation of Assertion B. Both Assertion and Reason are correct but the Reason is not the correct explanation of the Assertion c. Assertion is correct but the Reason is incorrect D. Assertion is incorrect and Reason is correrct |
11 |
| 763 | What should be the kinetic energy of electron in the first orbit of hydrogen atom? |
11 |
| 764 | -bitat 7. The outermost electronic configuration of manganese (at. no. = 25) is (a) 3 dº 4s² (6) 3 dº 45 (6) 3d 45° (d) 3d 4s2 The energy needed to remova 1 |
11 |
| 765 | Which of the following is correct electronic configuration of argon? A. 2,8 B. 2,8,8 c. 2,8,1 D. 8,2,8 |
11 |
| 766 | If ( r ) is radius of first orbit, the radius of nth orbit of the ( mathrm{H} ) atom will be : ( A cdot m^{2} ) B. rn ( c cdot r / n ) ( D cdot r^{2} n^{3} ) |
11 |
| 767 | Read the table and answer the question below: ( begin{array}{llllll}text { Elements } & boldsymbol{A} & boldsymbol{B} & boldsymbol{C} & boldsymbol{D} & boldsymbol{E} \ begin{array}{l}text { MASS } \ text { NO. }end{array} & 1 & 7 & 14 & 40 & 40 \ begin{array}{l}text { Atomic } \ text { No. }end{array} & 1 & 3 & 7 & 18 & 20end{array} ) |
11 |
| 768 | Which of the following quantum numbers are correct for the outermost electron of sodium atom? A. ( n=4, l=0, m=0, s=pm 1 / 2 ) В. ( n=3, l=0, m=0, s=-1 / 2 ) c. ( n=3, l=1, m=pm 1, s=+1 / 2 ) |
11 |
| 769 | The energy of a photon is given as ( 3.03 times 10^{-19} ) J/atom. The wavelength of the photon is : ( A cdot 6.56 mathrm{nm} ) B. 65.6 nm c. ( 0.656 mathrm{nm} ) D. 656 nm |
11 |
| 770 | A free nucleus of mass 24 amu emits a gamma photon (when initially at rest). The energy of the photon is 7 MeV. The recoil energy of the nucleus in KeV is: (Assuming 1 amu ( =931 ) MeV ) A . 2.2 B. 1. c. ( 3 . ) D. 22 |
11 |
| 771 | What do you mean by degenerate orbitals? Give examples. | 11 |
| 772 | The maximum probability of finding electron in the ( d_{x y} ) orbital is: A. along with ( x ) – axis B. along the ( y ) -axis c. at an angle of 45 from the ( x ) and ( y ) axis D. at an angle of 90 from the ( x ) and ( y ) axis |
11 |
| 773 | 3. The wavelengths involved in the spectrum of deuterium GD) are slightly different from that of hydrogen spectrum because (a) the attraction between the electron and the nucleus is different in the two cases. (b) the size of the two nuclei is different. (c) the nuclear forces are different in the two cases. (d) the masses of the two nuclei are different. (AIEEE 2003) |
11 |
| 774 | The wave function for an orbital is ( boldsymbol{H}- ) atom is given as: ( mathbf{Psi}= ) ( left(frac{sqrt{2}}{81 sqrt{pi}}right)left(frac{1}{a_{0}}right)^{frac{2}{3}}left(6-frac{r}{a_{0}}right)left(frac{r}{a_{0}}right)^{-frac{r}{3 a}} ) The orbital is: ( A cdot 2 s ) в. ( 3 p ) ( c cdot 2 p ) D. ( 3 d ) |
11 |
| 775 | Canal rays are: A. alpha rays B. light emitted when an electron falls into the nucleus C. ionized gaseous atoms D. light emitted when electron comes from a higher orbit to lower orbit |
11 |
| 776 | State True or False. ( psi^{2} ) determines the probability of finding the electron in particular region of space. A. True B. False |
11 |
| 777 | What are the postulates of Bohr’s mode of an atom? |
11 |
| 778 | Einstein’s photo-electric equation states that ( boldsymbol{E}_{boldsymbol{k}}=boldsymbol{h v}-boldsymbol{W} . ) In this equation, ( boldsymbol{E}_{boldsymbol{k}} ) refers to: A. kinetic energy of all ejected electrons B. mean kinetic energy of emitted electrons c. minimum kinetic energy of emitted electrons D. maximum kinetic energy of emitted electrons |
11 |
| 779 | Based on the equation, ( boldsymbol{E}=-mathbf{2 . 0} times ) ( 10^{-18} frac{Z^{2}}{n^{2}} J, ) the wavelength of the light that must be absorbed to excite hydrogen electron from level ( n=1 ) to level ( n=2 ) will be: ( (h=6.625 times ) ( left.mathbf{1 0}^{-mathbf{3 4}} boldsymbol{J} s, boldsymbol{C}=mathbf{3} times mathbf{1 0}^{mathbf{4}} boldsymbol{m} boldsymbol{s}^{-1}right) ) A . ( 1.2 times 10^{-7} mathrm{m} ) В . ( 1.325 times 10^{-7} mathrm{m} ) c. ( 5.300 times 10^{-10} mathrm{m} ) D. ( 1.325 times 10^{-10} m ) |
11 |
| 780 | Iron has ( _{-}-_{-}-_{-}- ) isotopes | 11 |
| 781 | Assertion Orbit and orbital are synonymous. Reason A circular path around the nucleus in which an electron moves is called orbit or orbital. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 782 | The wave function for ( 1 s ) orbital of the hydrogen atom is given by [ mathbf{Psi}_{1 s}=frac{boldsymbol{pi}}{sqrt{mathbf{2}}} boldsymbol{e}^{-boldsymbol{r} / boldsymbol{a}_{0}} ] where ( a_{0}= ) Radius of first Bohr orbit ( r= ) Distance from the nucleus (Probability of finding the electron varies with respect to it) What will be the ratio of probabilities of finding the electrons at the nucleus to first Bohr’s orbit ( a_{0} ? ) ( A ) B ( cdot e^{2} ) ( c cdot 1 / e^{2} ) D. zero |
11 |
| 783 | ( N_{2}, C O, C N^{-} ) and ( N O^{+} ) are isoelectronic but the former is chemically inert and later three are very reactive, why? |
11 |
| 784 | Which is more hard, sponge or iron? | 11 |
| 785 | Which of the following quantities can only be a whole number? A. Atomic radius B. Atomic number c. Mass number D. Equivalent weight |
11 |
| 786 | What is the final velocity of an electron accelerating through a potential of 1600 ( V, ) if its initial velocity is zero? A ( .2 .37 times 10^{9} mathrm{ms}^{-1} ) В. ( 4.74 times 10^{7} mathrm{ms}^{-1} ) c. ( 2.37 times 10^{7} m s^{-1} ) D. None of these |
11 |
| 787 | Calculate the momentum of a particle which has a de Broglie wavelength of ( 2.5 times 10^{-10} m ) ( left(h=6.6 times 10^{-34} k g m^{2} s^{-1}right) ) |
11 |
| 788 | Watch column A mame or the Scientists) with column B (their contributions towards the understanding of the atomic structure). Column A Column ( mathbf{B} ) A. Ernest Rutherford 1. Indivisibility of atoms B. J.J Thompson 2. Stationary orbits C. Dalton 3. Concept of nucleus D. Neils Bohr 4. Discovery of electrons E. James Chadwick 5. Atomic number F. E Goldstein 6. Neutron G. Moseley ( quad ) 7. Canal rays ( mathbf{A} cdot A rightarrow 3, B rightarrow 4, C rightarrow 1, D rightarrow 2, E rightarrow 6, F rightarrow 7, G rightarrow 5 ) ( mathbf{B} cdot A rightarrow 3, B rightarrow 4, C rightarrow 6, D rightarrow 2, E rightarrow 1, F rightarrow 5, G rightarrow 5 ) ( mathbf{C} cdot A rightarrow 3, B rightarrow 4, C rightarrow 1, D rightarrow 2, E rightarrow 6, F rightarrow 5, G rightarrow 5 ) ( mathbf{D} cdot A rightarrow 3, B rightarrow 4, C rightarrow 1, D rightarrow 2, E rightarrow 5, F rightarrow 7, G rightarrow 6 ) |
11 |
| 789 | Define isobars and isotopes. | 11 |
| 790 | What will be the ratio between the radius of ( 3^{r} d ) shell of ( L i^{+2} & ) radius of ( 3^{r d} ) shell of the hydrogen atom? |
11 |
| 791 | If the uncertainty in velocities of two particles ( A ) and ( B ) with ( operatorname{mass} 1.0 x ) ( 10^{-27} k g ) and ( 1.0 times 10^{-31} k g ) respectively is same, the ratio of uncertainty in the positions of ( A ) and ( B ) is : A . 1000: B. 10,000: c. 1: 1000 D. 1:10,000 |
11 |
| 792 | What are isotopes? A. These are the forms of the same element having the same atomic number but different atomic masses due to different nuclear structure. B. These are the forms of the same element having the different atomic number but different atomic masses due to different nuclear structure. C. These are the forms of the same element having the same atomic number but same atomic masses due to different nuclear structure. D. none of these |
11 |
| 793 | Which rule explains the electronic configuration of chromium is ( [mathrm{Ar}] ) ( 3 d^{5} 4 s^{1} ) instead of ( [A r] 3 d^{4} 4 s^{2} ? ) A. Pauli’s exclusion principle B. Aufbau Principle c. Hund’s rule D. Heisenberg principle |
11 |
| 794 | Goldstein’s work with anode rays of ( boldsymbol{H}^{+} ) was apparently the first observation of the : A. protons B. electrons c. neutrons D. atoms |
11 |
| 795 | An iron ball has a mass of 35 gms and a speed of ( 50 mathrm{m} / mathrm{s} ). If the speed can be measured with in accuracy of ( 2 % ) then the uncertainty in the position is : A. ( 1.507 times 10^{-34} m ) В. ( 1.507 times 10^{-31} m ) c. ( 1.507 times 10^{-33} m ) D. ( 1.507 times 10^{-12} m ) |
11 |
| 796 | Which of the following orbitals has the lowest energy? A . ( 4 d ) B. ( 4 f ) c. ( 5 s ) D. ( 5 p ) |
11 |
| 797 | What is the wavelength of light emitted when the electron in hydrogen atom undergoes transition from the energy level with ( n=4 ) to energy level ( n=2 ? ) ( left(operatorname{given} R_{n}=109678 c m^{-1}right) ) A. 786 nm B. 486 nm c. ( 586 mathrm{nm} ) D. 986 nm |
11 |
| 798 | Which of the following spectra was not explained by Bohr’s Atomic model? This question has multiple correct options A. Spectra of single electron system B. Hydrogen spectra c. spectra other than Hydrogen like atoms D. spectra of helium atom |
11 |
| 799 | If the position of the electron is measured within an accuracy of ( pm ) ( 0.002 mathrm{nm}, ) calculate the uncertainty in the momentum of the electron. Suppose the momentum of the electron is ( frac{h}{4 pi m} times 0.05 n m, ) is there any problem in defining this value? | 11 |
| 800 | If ( R_{H} ) is the Rydberg constant, then the energy of an electron in the ground state of Hydrogen atom is: A ( cdot frac{-R_{H}}{c h} ) в. ( frac{-1}{R_{H} c h} ) c. ( frac{-h c}{R_{H}} ) D. ( -R_{H} h c ) |
11 |
| 801 | The atomic number is identical to the amount of ( _{—}-_{–} ) in the atom nucleus. A. Protons B. Neutrons c. Both a and D. None of above |
11 |
| 802 | Aufbau principle fails to explain the configuration of element with atomic number: ( A cdot 18 ) B . 21 ( c cdot 24 ) D. 27 |
11 |
| 803 | to determine the exact position and exact Q.50 Assertion (A) It is impossible to determine the exact position momentum of an electron simultaneously. Reason (R) The path of an electron in an atom is clearly defined. (a) Both A and R are true and R is the correct explanation of A (b) Both A and R are true but is not the correct explanation of A (c) A is true and R is false (d) Both A and Rare false |
11 |
| 804 | How many nodes are present in ( 3-mathrm{p} ) orbitals? Represent diagrammatically. | 11 |
| 805 | Calculate the wavelength and energy of radiation emitted for the electronic transition from infinite to stationary state of hydrogen atom. (Given, ( boldsymbol{R}= ) ( mathbf{1} . mathbf{0} mathbf{9 6 7} mathbf{8} times mathbf{1 0}^{mathbf{7}} mathbf{m}^{-mathbf{1}}, mathbf{h}=mathbf{6 . 6 2 5 6} times ) ( 10^{-34} J-s ) and ( c=2.9979 times 10^{8} m s^{-1} ) ) |
11 |
| 806 | Which of the following is one of the postulates of Rutherford’s theory? A. Electrons continuously lose energy B. Electrons move in a spiral path around the nucleus c. Electrons revolve in a specific path around the nucleus D. Electrons revolve in a stationary orbit |
11 |
| 807 | The approximate radius of polonium nucleus of mass number 210 is: ( mathbf{A} cdot 8 times 10^{-6} m ) B. ( 8 times 10^{-5} m ) ( mathbf{c} cdot 4 times 10^{-6} m ) D. none of these |
11 |
| 808 | Atoms of two elements ( P ) and ( Q ) have 5 electrons in ( 2^{n d} ) shell and ( 3^{r d} ) shell respectively. What could be the geometric representations of ( boldsymbol{P} ) and ( boldsymbol{Q} ) ? What will be the atomic numbers of these elements? |
11 |
| 809 | 10. Hydrogen atom is excited from ground state to another state with principal quantum number equal to 4. Then the number of spectral lines in the emission spectra will be (a) 2 (c) 5 (d) 6 (AIEEE 2012) (b) 3 11. com |
11 |
| 810 | How many spherical nodes are present in ( 4 s ) orbital in a hydrogen atom? A. 0 B. 2 ( c cdot 3 ) ( D ) |
11 |
| 811 | 2p orbitals have: A ( . n=1, l=2 ) B. ( n=1, l=0 ) c. ( n=2, l=1 ) D. ( n=2, l=0 ) |
11 |
| 812 | Consider a hypothetical atom where ( boldsymbol{p}_{boldsymbol{x}}, boldsymbol{p}_{boldsymbol{y}}, boldsymbol{p}_{boldsymbol{z}}, boldsymbol{d}_{boldsymbol{x} boldsymbol{y}}, boldsymbol{d}_{boldsymbol{x} z}, boldsymbol{d}_{boldsymbol{y} boldsymbol{z}} boldsymbol{a} boldsymbol{n} boldsymbol{d} boldsymbol{d} boldsymbol{x}^{2}-boldsymbol{y}^{2} ) orbital are present for principal quantum number ( n=3 ) Find the number of other orbitals whose lobes are fully present in the nodal plane of ( boldsymbol{p}_{boldsymbol{x}} ) orbital: ( A cdot 2 ) B. 3 ( c cdot 4 ) D. 5 |
11 |
| 813 | State True or False. Gamma rays are electromagnetic radiations of wavelengths of ( 10^{-6} mathrm{cm} ) to ( 10^{-5} mathrm{cm} ) A. True B. False |
11 |
| 814 | The light velocity of revolving electrons is conquered by ……….. force of attraction of nucleus on an electron in Rutherford’s model. A. electrostatic B. gravitational c. magnetic D. van der waals |
11 |
| 815 | The manganese ( (Z=25) ) has the outer configuration: ( A ) 45 ( uparrow downarrow ) B. 45 ( uparrow downarrow ) begin{tabular}{|c|c|c|c|c|} hline multicolumn{2}{|c|} {( 3 d )} & multicolumn{2}{|c|} {} \ hline( uparrow ) & ( uparrow ) & ( uparrow ) & ( uparrow ) & ( uparrow ) \ hline end{tabular} ( c ) begin{tabular}{c} ( 4 s ) \ hline( uparrow downarrow ) end{tabular} begin{tabular}{|c|c|c|c|} hline multicolumn{2}{|c|} {( uparrow d )} & multicolumn{2}{c|} {} \ hline( uparrow downarrow mid uparrow downarrow ) & ( uparrow ) & & \ hline end{tabular} ( D ) 45 |
11 |
| 816 | Which of the following has the maximum penetrating power? ( A cdot alpha- ) Jarticle B. Proton c. ( gamma ) – particle D. Positron |
11 |
| 817 | What are the main postulates of Bohr’s theory of an atom? | 11 |
| 818 | In which of the following energy of ( 2 s ) orbital is minimum. A . ( L i ) в. ( N a ) ( c . K ) D. ( H ) |
11 |
| 819 | The wavelength range of the visible spectrum extends from violet ( (400 n m) ) to red ( (750 n m) . ) Express these wavelengths in frequencies ( (boldsymbol{H} boldsymbol{z}) ) ( left(1 n m=10^{-9} mright) ) | 11 |
| 820 | The atoms in a molecule do not remain stationary. They vibrate around their mean position, by stretching or bending out of plane. We gain useful knowledge about these vibrations and the energy they carry by studying: A. ( X ) -ray spectra B. ultraviolet spectra c. infrared spectra D. visible spectra |
11 |
| 821 | How many elements will be present in ( 5^{t h} ) period of the periodic table? Justify using quantum numbers. |
11 |
| 822 | Calculate the mass number of atoms ( X, Y ) and ( Z ? ) A . 5,11,18 B. 10,18,31 c. 11,18,3 D. 11,19,30 |
11 |
| 823 | What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition, ( n= ) 4 to ( n=2 ) of ( H e^{+} ) spectrum? |
11 |
| 824 | Identify the correct ground state electrons configuration for ( boldsymbol{C r} ) : ( mathbf{A} cdot[A r] 3 s^{2} 3 d^{4} ) B . ( [A r] 3 s^{2} 3 d^{5} ) c. ( [A r] 4 s^{2} 3 d^{5} ) D ( cdot[A r] 4 s^{2} 3 d^{4} ) E ( cdot[A r] 4 s^{1} 3 d^{5} ) |
11 |
| 825 | What does the negative electronic energy (negative sign for all values of energy) for hydrogen atom means? A. The energy of an electron in the atom is lower than the energy of a free electron at rest which is taken as zero B. When the electron is free from the influence of nucleus it has a negative value which becomes more negative c. When the electron is attracted by the nucleus the energy is absorbed which means a negative value D. Energy is released by hydrogen atom in ground state |
11 |
| 826 | Write electronic configurations of the ( boldsymbol{H} e ) |
11 |
| 827 | The quantum numbers of most energetic electron in Ar atom when it is in first excited state is: A ( cdot_{2,1,0, pm} frac{1}{2} ) в. ( _{4,1,1, pm} frac{1}{2} ) c. ( _{4,0,0, pm} frac{1}{2} ) D. ( _{4,1,0, pm} frac{1}{2} ) |
11 |
| 828 | If moving with equal speeds, the longest wavelength of the following matter waves is that for a (an): A. electron B. ( alpha ) -particle c. proton D. neutron |
11 |
| 829 | The number of spherical nodes in ( 3 p ) orbital is/are: | 11 |
| 830 | The charge on ( alpha ) -particle is the charge on proton. A . twice B. thrice c. half D. same as |
11 |
| 831 | An atom has electronic configuration of 2,8,18,7 What is the atomic number the of atom? A. 7 B. 35 c. 70 D. 17 |
11 |
| 832 | Give the main drawback of Rutherford’s model. |
11 |
| 833 | The number of orbitals in ( n=3 ) are: ( mathbf{A} cdot mathbf{1} ) B. 4 ( c cdot 9 ) D. 16 |
11 |
| 834 | Which series have highest energy in hydrogen spectrum? A. Balmer c. Pfund D. Lyman |
11 |
| 835 | The speed of the electron in the 1 st orbit of the hydrogen atom in the ground state is: ( (c ) is the velocity of light) A ( cdot frac{c}{1.37} ) в. ( frac{c}{1370} ) c. ( frac{c}{13.7} ) D. ( frac{c}{137} ) |
11 |
| 836 | ( X ) -rays: A. are deflected in a magnetic field. B. are deflected in an electric field. C. remain undeflected by both electric and magnetic fields. D. are deflected in both electric and magnetic fields. |
11 |
| 837 | Which of the following species has more number of protons than the number of electrons? ( A cdot F^{-} ) в. ( N a^{+} ) ( c cdot O^{2} ) D. Ne |
11 |
| 838 | 36. A sample of hydrogen is bombarded by electrons. Through what potential difference should the electrons be accelerated so that third line of Lyman series be emitted? (a) 2.55 V (b) 10.2 V (c) 12.09 V (d) 12.75 V |
11 |
| 839 | For emission line of atomic hydrogen from ( n_{i}=8 ) to ( n_{f} ) – the plot of wave number ( (bar{v}) ) against ( left(frac{1}{n^{2}}right) ) will be: (The Rydberg constnt, ( R_{H} ) is in wave number unit). A . linear with slope ( -R_{H} ) B. linear with intercept – ( R_{H} ) c. non linear D. linear with slope ( R_{H} ) |
11 |
| 840 | Define the atomic mass unit. A. Mass unit equal to exactly one-twelfth the mass of a carbon-12 atom B. Mass unit equal to exactly the mass of a carbon-12 atom C. Mass unit equal to exactly one-twelfth the mass of a hydrogen atom D. All of the above |
11 |
| 841 | Complete the table given below ( begin{array}{ll}text { No. of } & text { No. of } \ text { Protons } & text { Electr }end{array} ) No. of Electrons Neutror ( _{13}^{35} C l ) [ _{17}^{37} C l ] |
11 |
| 842 | Atomic radius is of the order of ( 10^{-8} mathrm{cm} ) and nuclear radius is of the order of ( 10^{-13} mathrm{cm} . ) The fraction of atom occupied by nucleus is: A ( cdot 10^{-5} ) B . ( 10^{5} ) ( mathbf{c} cdot 10^{-15} ) D. none of these |
11 |
| 843 | Which of the following metals require radiation of highest frequency to cause emmission of electrons? A. ( N a ) в. ( M g ) ( c . k ) D. ( C a ) |
11 |
| 844 | How many unpaired electrons are there in ( mathrm{Ni}^{2+} ) ? ( A cdot O ) B. 2 ( c cdot 4 ) D. 8 |
11 |
| 845 | An excited hydrogen atom emits a photon of wavelength ( lambda ) in returning to the ground state. If ( R ) is the Rydberg constant, then the quantum number ( n ) of the excited state will be: ( A cdot sqrt{lambda R} ) B. ( sqrt{lambda R-1} ) c. ( sqrt{frac{lambda R}{lambda R-1}} ) D. ( sqrt{lambda R(lambda R-1)} ) |
11 |
| 846 | Out of given atoms which atoms has highest energy of 2 s-subshell ? A . B. Li c. Na D. All have same |
11 |
| 847 | Which of the following graphs represents the correct variations for De Broglie wavelengths of electrons: ( A ) B. ( c ) D. none |
11 |
| 848 | Adding an alpha particle to nucleus of sodium atom, product will be A . ( N a^{text {t }} ) в. ( M g^{2+} ) c. ( A l^{2} ) D. ( A l ) |
11 |
| 849 | A golf ball has mass of ( 30 g ) and a speed of ( 50 mathrm{m} / mathrm{s} ). If the speed can be measured within accuracy of ( 1 % ) then uncertainty in the position is: A. ( 2.4 times 10^{-32} mathrm{m} ) В. ( 3.5 times 10^{-33} mathrm{m} ) c. ( 3.5 times 10^{-34} mathrm{m} ) D . 2.4 ( times 10^{-33} mathrm{m} ) |
11 |
| 850 | 62. Transitions between three energy levels in a particular atom give rise to three spectral lines of wavelengths, in increasing magnitudes, 21, 22, and ls. Which one of the following equations correctly relates 21, 22, and is? (a) a = – dz (b) 2 = 2z – 1 (d) 1 1 (c) +-11 2 ata 21 22 23 21 22 22 |
11 |
| 851 | Q66. Indicate the number of unpaired electrons in : (a) P (b) Si (c) Cr (d) Fe and (e) Kr. |
11 |
| 852 | Emission of ( beta ) -particles by an atom of an element results in the formation of A. isobar B. isomer ( c . ) isotope D. isotone |
11 |
| 853 | Q3. What were the weaknesses or limitations of Bohr’s model of atoms? Briefly describe the quantum mechanical model of atom. |
11 |
| 854 | Assertion To overcome electrostatic force of attraction between electrons and nucleus, they revolve around the nucleus. Reason Mass of the atom is almost due to its nucleus. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion. B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion. C. Assertion is correct but Reason is incorrect. D. Assertion is incorrect but Reason is correct. |
11 |
| 855 | Q10. What is the difference between ground state and excited state? L. TALL. the plante |
11 |
| 856 | 58. When the hydrogen atom emits a photon in going from n = 5 to n = 1 state, its recoil speed is nearly (a) 104 m s-1 (b) 2 x 10-2 ms (c) 4 m s-1 (d) 8 x 102 ms-1 |
11 |
| 857 | Identify the correct statement(s) from the following. This question has multiple correct options A. The ion having a positive charge on it is known as electro – positive ion. B. The ion having a negative charge on it is known as electro – negative ion. C. Simple ion is an ion which contains one or more atoms of the same element. D. Compound ion is an ion which contains two or more atoms of different elements forming a single unit. |
11 |
| 858 | When electrons in sample of H-atom make transitions from 5th excited state to ground state, then the maximum number of spectral lines which belong to visible region is: A . 10 B. 4 c. 15 D. 5 |
11 |
| 859 | 29. A hydrogen-like atom emits radiations of frequency 2.7 x 1015 Hz when it makes a transition from n = 2 to n = 1. The frequency emitted in a transition from n = 3 to n= 1 will be (a) 1.8 x 10 Hz (b) 3.2 x 10 Hz (c) 4.7 x 10 Hz (d) 6.9 x 10 Hz |
11 |
| 860 | The most probable radius (in pm) for finding the electron in ( boldsymbol{H} boldsymbol{e}^{+} ) is: A . ( 0 . ) в. 52.9 c. 26.45 D. 105.8 |
11 |
| 861 | Which is correct relationship? ( mathbf{A} cdot E_{1} ) of ( H=frac{1}{2} E_{2} ) of ( mathrm{H} e^{+}=frac{1}{3} E_{3} ) of ( L i^{+2}= ) ( frac{1}{4} E_{4} ) of ( B e^{+3} ) B ( cdot E_{1}(H)=E_{2}left(H e^{+}right)=E_{3}left(L i^{+2}right)=E_{4}left(B e^{+3}right) ) C ( cdot E_{1}(H)=2 E_{2}left(H e^{+}right)=3 E_{3}left(L i^{+2}right)=4 E_{4}left(B e^{+3}right) ) D. No relation |
11 |
| 862 | 9. The maximum number of electrons in a sub-shell is given by the equation (a) n² (6) 2n? (c) 21-1 (d) 21 +1 TE |
11 |
| 863 | Which one of the following explains light both as a stream of particles and as wave motion? A . Diffraction в. ( lambda=h / p ) c. Interference D. Photoelectric effect |
11 |
| 864 | State True or False. The three quantum numbers were clearly explained in terms of Schrodinger wave equation. A. True B. False |
11 |
| 865 | If the speed of electron in the Bohr’s first orbit of hydrogen is ( x, ) the speed in the third orbit is: A. ( x / 9 ) B. ( x / 3 ) ( c .3 x ) D. ( 9 x ) |
11 |
| 866 | Which of the following does not contain material particles? A. ( alpha ) -rays B. ( beta ) -rays c. ( gamma ) -rays D. Anode rays |
11 |
| 867 | 54. A beam of electron accelerated by a large potential difference V is made to strike a metal target to produce X-rays. For which of the following values of V, will the resulting X-rays have the lowest minimum wavelength? (a) 10 kV (b) 20 kV (c) 30 kV (d) 40 kV |
11 |
| 868 | Which among the following statements is/are correct? This question has multiple correct options A. ( Psi^{2} ) represents the atomic orbitals B. The number of peaks in radial distribution is ( (n-1) ) C . Radial probability density ( rho_{n l}(r)=4 pi r^{2} R_{n l}^{2}(r) ) D. A node is a point in space where the wave function has zero amplitude |
11 |
| 869 | Which element has electrons in ( f ) orbitals? ( A cdot A r ) B. ( c cdot s ) D. Ti E. |
11 |
| 870 | Calculate the mass of a photon of sodium light having wavelength ( 5894 A ) and velocity ( 3 times 10^{8} mathrm{m} / mathrm{s} ) ( left(h=6.6 times 10^{-34} K g m^{2} s^{-1}right) ) |
11 |
| 871 | The wave length of second line in the Balmer series of hydrogen spectrum is equal to: (R=Rydberg constant) ( mathbf{A} cdot 36 / 5 R ) в. ( 5 R / 36 ) c. ( 3 R / 16 ) D. ( 16 / 3 R ) |
11 |
| 872 | The atomic number of an element ( X ) is 13.What will be the number of electrons in its ion ( X^{34} ) |
11 |
| 873 | An ( alpha ) -particle is identical with: A. proton B. neutron c. helium nucleus D. electron |
11 |
| 874 | ( ^{210} 84^{circ} mathrm{o} longrightarrow_{82}^{206} mathrm{Pb}+_{2}^{4} mathrm{He} ) In this reaction, predict the position of group of ( P o ) in periodic table when lead is in the ( I V A ) group: A . IIA в. ( I V B ) c. ( V I A ) D. ( V I B ) |
11 |
| 875 | Which of the following is the main cause of late discovery of neutron? A. Neutron is highly unstable particle B. Neutron in nucleus moves very fast c. Neutron is charge-less particle D. All of the above |
11 |
| 876 | Assertion The mass number of an atom is the sum of number of protons and neutrons it contains. Reason The mass number of an atom can never be smaller than the atomic number. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion. B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 877 | Which of the following are isoelectronic species? (i) ( boldsymbol{N} boldsymbol{H}_{mathbf{3}} ) (ii) ( boldsymbol{C} boldsymbol{H}_{3}^{+} ) (iii) ( boldsymbol{N} boldsymbol{H}_{mathbf{2}}^{-} ) (iv) ( boldsymbol{N} boldsymbol{H}_{mathbf{4}}^{+} ) Choose the correct answer from the codes given below: A ( cdot(i),(i i),(i i i) ) B. (i),(iii), (iv) C . ( (i),(i i),(i v) ) D. ( (i i),(i i i) ) E. None of these |
11 |
| 878 | X-rays emitted from a copper target and a molybdenum target are found to contain a line of wavelength ( 22.85 mathrm{nm} ) attribute to the ( K_{alpha} ) lines of an impure element. The ( K_{alpha} ) lines of copper ( (mathrm{Z}=29 ) and molybdenum ( (mathrm{Z}=42) ) have a wavelength 15.42 nm and 7.12 nm respectively. Using Moseley’s law, ( v^{1 / 2}=a(Z-b), ) calculate the atomic number of the impure element: A .24 B . 28 c. 30 D. 32 |
11 |
| 879 | State True or False. The properties of elements are periodic function of their atomic number A. True B. False |
11 |
| 880 | Protons and neutrons are also called A . nucleons B. isotope c. isobars D. elements |
11 |
| 881 | Rutherford’s scattering formula fails for very small scattering angles because: This question has multiple correct options A. the gold foil is very thin B. the kinetic energy of ( alpha ) -particles is very high C. the full nuclear charge of the target atom is partially screened by its electron D. there is strong repulsive force between the ( alpha ) -particles and nucleus of the target |
11 |
| 882 | 42. When a metal is heated in a flame, the electrons absorb en- ergy and jump to higher energy state. On coming back to the low- er energy siate, they emit light, which we can observe in (1) Raman spectra (2) Absorption spectra (3) Emission spectra (4) Fluorescence |
11 |
| 883 | The wavelength of light wave of wave number ( 4000 mathrm{cm}^{-1} ) is: |
11 |
| 884 | 22. In a hydrogen atom, the transition takes place place from n=3 to n = 2. If Rydberg’s constant is 1.09 x 10 the wavelength of the line emitted is (a) 6606 X (b) 4861 A (c) 4340 Å (d) 4101 A |
11 |
| 885 | Which of the following statements on the atomic wave function ( Psi ) is not correct? A. ( Psi ) may be a real valued wave function B. ( Psi ) may be in some cases be a complex function c. ( Psi ) has a mathematical significance only D. ( Psi ) is proportional to the probability of finding an electron |
11 |
| 886 | An orbital made of four lobes can have the following quantum numbers: A ( cdot n=2,1=2, m=0 ) B. ( n=3,1=1, m=-2 ) ( c cdot n=3,1=2, m=0 ) D. ( n=3,1=3, m=-3 ) |
11 |
| 887 | Radioactive disintegration differs from a chemical change in being: A. an exothermic change B. a spontaneous process c. a nuclear process D. a unimolecular first-order reaction |
11 |
| 888 | An isotope of helium is represented by the symbol ( _{2}^{3} H e . ) How many protons, neutrons and electrons are there in an atom of the isotope? A. 1 proton, 2 neutrons, 1 electron B. 1 proton, 3 neutrons, 2 electrons C. 2 protons, 1 neutron, 2 electrons D. 2 protons, 3 neutrons, 2 electrons |
11 |
| 889 | Which of the following orbitals is closer to nucleus? ( A cdot 5 f ) B. 6d ( c cdot 7 s ) D. ( 7 p ) |
11 |
| 890 | In hydrogen atom, energy of first excited state is ( -3.4 e V . ) Then find out the ( K E ) of the same orbit of hydrogen atom. A. +3.4 eV B. ( +6.8 e V ) c. ( -13.6 e V ) D. ( +13.6 e V ) |
11 |
| 891 | Q22. What is difference between the notations 1 and L? Y |
11 |
| 892 | An atom does not carry any electric charge because it A. has an equal number of charged and non charged particles B. has neutrons in their nuclei C. has an equal number of electrons and protons, hence positive and negative charge gets neutralized. D. has an equal number of neutrons and protons |
11 |
| 893 | What was the requirement for introducing atomic orbital concept? | 11 |
| 894 | Which of the following statements is not true? A. The ratio of the mean speed of the RMS speed is independent of the temperature B. The square of the mean speed of the molecules is equal to the mean square speed at a certain temperature C. Mean kinetic energy of the gas-molecules at any given temperature is independent of the mean speed D. The difference between RMS speed and mean speed at any temperature for different diminishes as larger and yet larger molar masses are considered |
11 |
| 895 | Which one of the following sets of ions represent the collection of isoelectronic species? A ( cdot K^{+}, C a^{2+}, S c^{3+}, C l^{-} ) B. ( N a^{+}, M g^{2+}, A l^{3+}, C l^{-} ) C ( cdot K^{+}, C l^{-}, M g^{2+}, S c^{3+} ) D. ( N a^{+}, C a^{2+}, S c^{3+}, F^{-} ) |
11 |
| 896 | As per Bohr’s model, an electron in an uni-electronic species revolves around the nucleus in circular orbits. What is the radius of the 3 rd orbit of ( boldsymbol{H} boldsymbol{e}^{+} ) ion? A ( .2 .38 AA ) В. ( 1.19 dot{A} ) c. ( 0.7 dot{h} ) D. ( 4.76 AA ) |
11 |
| 897 | We have four substances ( mathrm{P}, mathrm{Q}, mathrm{R}, mathrm{S} ) Substance ( P ) is dark coloured violet solid having diatomic molecules. Solution of ( P ) in alcohol is an Antiseptic ‘T’ Substance ‘Q’is a white solid usually recovered from sea on a large scale. Substance ‘R’ is also a white solid insoluble in water and used in the form of small balls for safe storage of woolen clothes. Substance ‘S’ is a white solid too used in dry cell. P,Q,R,S,T, may be (choose correct option) A. P-lodine, Q-Napthalene,R- ( R-N H_{4} C I ) S-Nacl, T-lodin tincture B. P-NaCI,Q-Napthalene, ( R-N H_{4} C I ) S-lodine, T-lodine tincture C. P-lodine tincture, Q- ( R-N H_{4} C I R ) – lodine, S- Napthalene, T-NaCl D. P-lodine, Q-Nacl, R- Napthalene S- ( R-N H_{4} C I, ) T-lodine tincture |
11 |
| 898 | The probability ( (P) ) of survival of ( a ) radioactive nucleus in its mean life is: ( A cdot frac{1}{e} ) B. ( frac{1}{lambda} ) c. ( frac{0.633}{lambda} ) D. |
11 |
| 899 | The orbital with zero orbital angular momentum is : A . s B. ( c cdot d ) ( D ) |
11 |
| 900 | Q.5 Which of the following statements about the electron is incorrect? (a) It is a negatively charged particle (b) The mass of electron is equal to the mass of neutron (c) It is a basic constituent of all atoms (d) It is a constituent of cathode rays |
11 |
| 901 | If Aufbau rule is not followed in filling of sub orbitals, then block of the element will change in: A. K(19) (i) (19) (19) 19 B. ( operatorname{Sc}(21) ) ( c cdot v(23) ) ( D cdot N i(28) ) |
11 |
| 902 | Principal quantum number defined for A. shell B. subshell c. orbital D. spin |
11 |
| 903 | The space between proton and electron in hydrogen atom is : A. absolutely empty B. full of electromagnetic radiation C. full of air D. full of ether |
11 |
| 904 | Rutherford’s scattering experiment led to the conclusion that: A. nucleus is very small in size B. nucleus is very heavy and carries positive charge C. most of the space in the atom is empty D. all of these |
11 |
| 905 | The first emission line in the atomic spectrum of hydrogen in the Balmer series appears at: A ( cdot frac{9 R}{400} c m^{-1} ) B. ( frac{7 R}{144} mathrm{cm}^{-1} ) ( ^{mathrm{C}} cdot frac{3 R}{4} c m^{-1} ) D. ( frac{5 R}{36} c m^{-1} ) |
11 |
| 906 | The angular momentum of an electron in the ( 2^{n d} ) excited state ofa Helium ion ( left(boldsymbol{H} boldsymbol{e}^{+}right) ) is: A ( cdot frac{h}{2 pi} ) в. ( frac{2 h}{2 pi} ) ( c cdot frac{3 h}{2 pi} ) D. ( frac{4 h}{2 pi} ) |
11 |
| 907 | Wave functions of electrons in atom and molecules are called: A. orbitals B. azimuthal quantum number c. orbits D. degenerate orbitals |
11 |
| 908 | Cathode rays have: A. mass only B. charge only C. both mass and charge D. neither mass nor charge |
11 |
| 909 | 66. An electron revolving in an orbit of radius 0.5 A in a hydrogen atom executes 10° revolutions per second. The magnetic moment of electron due to its orbital motion will be (a) 1.256 x 10-23 A m² (b) 653 x 10-26 A m? (c) 10-3 A m (d) 256 x 10-26 A m |
11 |
| 910 | The spaces between molecules is least in : A. Solid B. Liquid c. Gases D. Vapour |
11 |
| 911 | The atom ( A, B, C ) have the configuration ( A rightarrow[Z(90)+n(146)], B rightarrow[Z(92)+ ) ( mathrm{n}(146)], mathrm{C} rightarrow[mathrm{Z}(90)+mathrm{n}(148)] ) So that (a) ( A ) and ( C- ) Isotones (b) A and C – Isotopes (c) ( A ) and ( B ) – Isobars (d) ( B ) and ( c- ) Isobars (e) ( mathrm{B} ) and ( mathrm{C} ) – Isotones The wrong statements are: A. a, bonly B. c, d, e only c. a ( , c, d ) only D. a, d, e only |
11 |
| 912 | -0- 1515 0 04. What is the most important application of de Broglie concept: measurement of |
11 |
| 913 | Write electronic configurations of the Sodium. | 11 |
| 914 | The orbital having minimum ( l ) value is: A. spherical in shape B. dumbell in shape c. double dumbell in shape D. tetrahedral in shape |
11 |
| 915 | Bohr’s atomic model is based on the following postulates: This question has multiple correct options A. an atom consists of nucleus. B. an electron can rotate only in certain energy levels. C . an electron remains moving with continuous loss of energy. D. none of the above. |
11 |
| 916 | Among the following which one contains valence electrons in the ground state of the magnesium ( M g ) atom? A . ( 1 s ) B . ( 2 s ) c. ( 3 s ) D. ( 3 p ) E . ( 3 d ) |
11 |
| 917 | State True or False. The electron distribution is spherically symmetrical for ( l=2 ) A. True B. False |
11 |
| 918 | Responsible for most helium found on Earth: A. Gamma decay B. Nuclear fusion c. Alpha decay D. Positron emission E. Nuclear fission |
11 |
| 919 | The electron density in the xy-plane in ( 3 d_{x^{2}-y^{2}} ) orbital is zero. If true enter 1 else enter 0 |
11 |
| 920 | Define matter. | 11 |
| 921 | Assertion The configuration of ( B ) -atom cannot be ( 1 s^{2} 2 s^{2} ) Reason Hund’s rule demands that the configuration should display maximum multiplicity. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion. B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 922 | Which of the following spectrochemical series is true? A ( cdot S C N^{-}<N H_{3}<F^{-}<e n<C O ) B . ( S C N^{-}<F^{-}<N H_{3}<e n<C O ) c. ( S C N^{-}<F^{-}<e n^{-}<N H_{3}<C O ) D. ( S C N^{-}<F^{-}<e n^{-}<C O^{-}<N H_{3} ) |
11 |
| 923 | The quantum number ‘m’ of a free gaseous atom is associated with: A. the effective volume of the orbital B. the shape of the orbital C. the spatial orientation of the orbital D. the energy of the orbital in the absence of a magnetic field |
11 |
| 924 | Assertion: Angular momentum of an electron in any orbit is given by angular momentum ( =frac{n . h}{2 pi}, ) where ( n ) is the principal quantum number. Reason: The principal quantum number, ( n, ) can have any integral value. A. If both assertion and reason are true and the reason is a correct explanation of the assertion. B. If both assertion and reason are true but reason is not a correct explanation of the assertion C. If the assertion is true but reason is false D. If both the assertion and reason are false E. If the assertion is false but the reason is true |
11 |
| 925 | The radiations suffers maximum deflection in a magnetic field is: A. ( alpha ) -particles B. ( beta ) -particles c. ( x ) -rays D. ( gamma ) -radiations |
11 |
| 926 | The maximum no. of electrons having parallel spin in the configuration ( 4 s^{2} 4 p^{5} ) are: ( A cdot 7 ) B. 4 ( c .3 ) D. 5 |
11 |
| 927 | According to Bohr’s model, the angular momentum of an electron in 4th orbit is: ( mathbf{A} cdot h / 3 ) B. ( h / 2 ) c. ( 2 h / pi ) D. none of these |
11 |
| 928 | Energy of the electron in Bohr’s orbit is equal to? A. potential energy only B. Kinetic energy only c. Sum of potential and kinetic energy D. difference of kinetic and potential energy |
11 |
| 929 | ( 4 s^{2} ) is the configuration of the outermost orbit of an element. Its atomic number would be: A . 29 B. 24 ( c . ) 30 D. 19 |
11 |
| 930 | Electron was discovery by J.J. Thomson A. True B. False |
11 |
| 931 | The amount of energy required to remove an electron from ground sate of ( H e^{+} ) ion is: A. -54.4 ev B . -13.6 ev c. -24.4 ev D. -34 ev |
11 |
| 932 | A transition metal ‘X’ has a configuration ( [mathrm{Ar}] 3 d^{4} ) in its +3 oxidation state, its atomic number is: A . 25 B . 26 ( c cdot 22 ) D. 19 |
11 |
| 933 | Q. 4 Which of the following statement is not correct about the characteristic of cathode rays? (a) They start from the cathode and move towards the anode (b) They travel in straight line in the absence of an external electrical or magnet field (c) Characteristics of cathode rays do not depend upon the material of electrodes is cathode ray tube (d) Characteristics of cathode rays depend upon the nature of gas present in the cathode ray tube |
11 |
| 934 | HMS. CUSH Tays a ys > Tauluk Q9. Which series of lines of the hydrogen spectrum lie in the visible region? |
11 |
| 935 | Rutherfords alpha particle scattering experiment concluded that: A. mass and energy are related B. electrons occupy space around the nucleus C. neutrons are buried deep in the nucleus D. the point of impact with matter can be precisely determined |
11 |
| 936 | c) T. 1 10111 (u) 0.04 10 11 27. The work function for sodium surface is 2.0 eV and that for aluminium surface is 4.2 eV. The two metals are illuminated with appropriate radiations so as to cause photoemission. Then (a) the threshold frequency for sodium will be less than that for aluminium (b) the threshold frequency of sodium will be more than that of aluminium (c) both sodium and aluminium will have the same threshold frequency (d) none of the above 0 c . 11. 1 1 . |
11 |
| 937 | According to Maxwell electromagnetic theory, through which path an electron should fall into the nucleus in Rutherford’s atomic model: A. Circular B. Spiral c. Zig-zag D. Straight line |
11 |
| 938 | Find the number of spectral line in Paschen series emitted by atomic ( boldsymbol{H} ) when electron excited from ground state to ( 70^{t h} ) energy level return back. |
11 |
| 939 | U10 5. How many photons of a radiation of wavelength 1= 5 x 10 m must fall per second on a blackened plate in order to produce a force of 6.62 x 10-‘N? (a) 3 x 1019 (b) 5 x 1022 (c) 2 x 1022 (d) 1.67 x 1018 |
11 |
| 940 | Q. 24 Nickel atom can lose two electrons to form Ni2+ ion. The atomic number of nickel is 28. From which orbital will nickel lose two electrons? Toutermost |
11 |
| 941 | What is common between given cations and anions : ( boldsymbol{O}^{2-}, boldsymbol{F}^{-}, boldsymbol{N} boldsymbol{a}^{+}, boldsymbol{M} boldsymbol{g}^{2+}, boldsymbol{A} boldsymbol{l}^{3+} ? ) A. All have same ionic radii B. All are isoelectronic species having 10 electrons c. All of them belong to the third period D. The nature of oxides of all the ions is basic |
11 |
| 942 | Monazite sample contains ( 9 % T h O_{2} ) and ( 0.35 % U_{3} O_{8} . P b^{208} ) and ( P b^{208} ) are the stable end products in the radioactive decay series of ( boldsymbol{T} boldsymbol{h}^{238} boldsymbol{q u a d a n d} quad mathbf{2 3 8} ) respectively. All the lead in monazite is of radiogenic origin. The isotopic ratio of ( P b^{208} T h^{232} ) was |
11 |
| 943 | In the equation ( boldsymbol{h} boldsymbol{v}=boldsymbol{h} boldsymbol{v}_{0}+frac{1}{2} boldsymbol{m}_{e} boldsymbol{v}^{2}, boldsymbol{v}_{0} ) is known as: A. work function B. velocity of ejected electron c. threshold frequency D. frequency of photon |
11 |
| 944 | Write the symbols of the first ten elements in the periodic table with the atomic numbers. | 11 |
| 945 | All types of electromagnetic radiations possess same: A. wavelength B. frequency c. energy D. velocity when passed through vacuum |
11 |
| 946 | State whether the given reaction is true or false: Heavy water is used to control nuclear |
11 |
| 947 | Meitnerium is IUPAC official name of an element with atomic number? ( A cdot 113 ) B. 118 ( c cdot 104 ) D. 109 |
11 |
| 948 | What is the nucleos number of an atom? A. The number of electrons, neutrons and protons in the nucleus B. The number of neutrons and protons in the nucleus C. The number of neutrons in the nucleus D. The number of protons in the nucleus |
11 |
| 949 | Isobars have: A. same mass number but different atomic number B. same number of neutrons but different mass number C. same difference between number of protons and neutrons D. same mass number and atomic number |
11 |
| 950 | Which of the following explains the reason for nitrogen’s three unpaired electrons? A. Hund’s rule B. Aufbau principle c. Pauli’s principle D. Heisenberg’s principle |
11 |
| 951 | For which of the following particles will it be most difficult to experimentally verify the de-Broglie relationship? A. an electron B. a proton c. an ( alpha ) particle D. a dust particle |
11 |
| 952 | Which of the following is true regarding an ( N e ) atom with a mass number of 20 and an ( O^{2-} ) ion with a mass number of ( 16 ? ) A. They contain the same number of protons. B. They contain the same number of neutrons. C. They contain the same number of protons plus neutrons. D. They are isoelectronic. |
11 |
| 953 | What will be the ratio of ( C l^{35} ) and ( C l^{37} ) respectively in chlorine if the average atomic mass of chlorine is ( 35.5 ? ) A . 1: B. 2:1 c. 3: 1 D. 3:2 |
11 |
| 954 | Write short note on solar spectrum or continuous spectrum |
11 |
| 955 | The electrons identified by quantum numbers ( n ) and ( l, ) are as follows: I. ( boldsymbol{n}=mathbf{4}, boldsymbol{l}=mathbf{1} ) Il. ( boldsymbol{n}=mathbf{4}, boldsymbol{l}=mathbf{0} ) III. ( boldsymbol{n}=mathbf{3}, boldsymbol{l}=mathbf{2} ) IV. ( n=3, l=1 ) If we arrange them in order of increasing energy, i.e. from lowest to highest, the correct order is: A. ( I V<I I<I I I<I ) B. ( I I<I V<I<I I ) c. ( I<I I I<I I<I V ) D. III ( <I<I V<I I ) |
11 |
| 956 | Consider the isoelectronic species, ( N a^{+}, M g^{2+}, F^{-} ) and ( O^{2-} . ) The correct order of increasing length of their radii is: A ( cdot F^{-}<O^{2-}<M g^{2+}<N a^{+} ) B. ( M g^{2+}<N a^{+}<F^{-}<O^{2} ) C. ( O^{2-}<F^{-}<N a^{+}<M g^{2+} ) D. ( O^{2-}<F^{-}<M g^{2+}<N a^{+} ) |
11 |
| 957 | Which of the following nuclides belong to actinium ( left(U^{235}right) ) series? This question has multiple correct options ( mathbf{A} cdot P b^{207} ) B . ( P o^{215} ) c. ( P_{o^{213}} ) D. ( _{1} H^{3} ) |
11 |
| 958 | Isoelectronic species have same number of electrons. A. True B. False |
11 |
| 959 | Define an atomic orbital. | 11 |
| 960 | The number of neutrons present in the deuterium isotope of hydrogen is A .2 B. 3 ( c cdot 5 ) ( D ) |
11 |
| 961 | The expression for de Broglie wavelength is : A ( cdot p=frac{h}{lambda} ) в. ( p=frac{h}{2 lambda} ) c. ( _{p}=frac{2 pi}{h lambda} ) D. ( p=frac{2 pi}{lambda} ) |
11 |
| 962 | Chemical properties of of an element are same, but their physical properties may be different A. isotopes B. isobars c. neutron D. proton |
11 |
| 963 | The ( d ) -orbital having two lobes and one doughnut is: ( mathbf{A} cdot d_{x^{2}-y^{2}} ) B. ( d_{z} ) c. ( d_{x y} ) D. ( d_{y z} ) |
11 |
| 964 | Which of the following is not a drawback of Rutherford’s model? A. Rutherford did not mention any direct link between the charge of the nucleus and the atomic mass B. He did not mention the relation between the charge of the nucleus and atomic number C. Both A and B D. None of these |
11 |
| 965 | Assertion ( mathbf{Psi} ) indicates the amplitude of electron – wave Reason ( mathbf{Psi}^{2} ) denotes the probability of finding an electron in the space around the nucleus. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
11 |
| 966 | The p-orbitals are directed towards ( X, Y ) ( mathbf{Z} ) coordinates and are at right angles to one another. A. True B. False |
11 |
| 967 | ( B e^{3+} ) and a proton are accelerated by same proton, their de-broglie wavelengths are in the ratio: (Assume the mass of proton=mass of neutron) A . 1: B. 1: ( c cdot 1: 4 ) D. ( 1: 3 sqrt{3} ) |
11 |
| 968 | Calculate the minimum and maximum number of electrons which may have magnetic quantum number, ( boldsymbol{m}=+mathbf{1} ) and spin quantum number, ( s=-frac{1}{2} ) in Chromium ( (mathrm{Cr}) ) A . 0,1 в. 1,2 c. 4,6 D. 2, |
11 |
| 969 | The frequency of the spectral line obtained when the electron in ( n=3 ) of Hydrogen atom drops to the fround state is: A ( cdot 2.925 times 10^{15} ) Hertz B . ( 2.925 times 10^{13} ) Hertz C . ( 2.925 times 10^{14} ) Hertz D. ( 36559 times 10^{10} ) Hertz |
11 |
| 970 | Which of the following observations were obtained from ( alpha ) -particle scattering experiment? A. Most of the fast moving ( alpha ) -particles passed straight through the gold foil B. Some of the ( alpha ) -particles were deflected by the foil by small angles c. One out of every 12000 particles appeared to rebound D. All of the above |
11 |
| 971 | What is the shape of d-orbital? A. spherical B. dumb bell c. double dumb bell D. no definite shape |
11 |
| 972 | Assertion e/m ratio of anode rays is independent of nature of gas. Reason All anode rays are protons A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 973 | Write all the four quantum no.for ( boldsymbol{p}- ) electrons of ( _{7} mathbf{N}^{14} ) A ( cdot n=3, l=2, m=-1,0,+1 ; s=+frac{1}{2} ) and ( -frac{1}{2} ) B. ( n=2, l=1, m=-1,0,+1 ; s=+frac{1}{2} ) or ( -frac{1}{2} ) c. ( _{n=2, l=1, m=-1,0,+1 ; s=+frac{1}{2}} ) D. ( n=2, l=0, m=0 ; s=+frac{1}{2} ) and ( -frac{1}{2} ) |
11 |
| 974 | ( B e^{3+} ) and a proton are accelerated by the same potential, their de-Broglie wavelenghts have the ratio (assume mass of proton ( = ) mass of neutron): A .1: 2 B. 1: 4 c. 1: 1 D. ( 1: 3 sqrt{3} ) |
11 |
| 975 | The ratio of the energy of a photon of ( 2000 A ) wavelength radiation to that of ( 4000 A ) radiation is: A ( cdot frac{1}{4} ) B. 4 ( c cdot frac{1}{2} ) D. 2 |
11 |
| 976 | Calculate maximum number of electrons in ( _{25} M n ) which have ( n=3, m=0 ) and ( s==1 / 2 ) |
11 |
| 977 | An electron of a velocity ( x ) is found to have a certain wavelength. The velocity to be possessed by the neutron to have half the de Broglie wavelength possessed by electron is: A ( cdot frac{x}{1840} ) в. ( frac{x}{920} ) c. ( 3680 x ) D. ( frac{x}{3680} ) |
11 |
| 978 | Which one of the following has a larger wave number? A . Red B. Blue c. Green D. Violet |
11 |
| 979 | Which of the following statement about quantum number is correct? This question has multiple correct options ( A . ) If the value of ( l=0, ) the electron distribution is spherical B. The shape of orbital is given by subsidiary quantum number C. The Zeeman’s effect is explained by magnetic quantum number D. The spin quantum number gives the orientations of electron cloud |
11 |
| 980 | Out of first 100 elements no.of elements having electrons in ( 3 d ) orbital (in their complete electronic configuration) are:- A . 80 в. 100 c. 40 D. 60 |
11 |
| 981 | Principal quantum number gives the of an electron and its distance from the nucleus. A. angular momentum B. energy c. velocity D. centrifugal force |
11 |
| 982 | Elements after atomic number 103 have not been discovered till now. If an element with atomic number 106 were ever discovered which of the following electronic configuration will it possess. ( mathbf{A} cdot[R n] 5 f^{14} 6 d^{4} 7 s^{1} ) B ( cdot[R n] 5 f^{14} 6 d^{5} 7 s^{1} ) ( mathbf{c} cdot[R n] 5 f^{14} 6 d^{6} 7 s^{0} ) D cdot ( [R n] 5 f^{14} 6 d^{1} 7 s^{2} 7 p^{3} ) |
11 |
| 983 | A ( d ) -subshell in an atom in the presence and absence of magnetic field is: A . five-fold degenerate, non-degenerate B. feven-fold degenerate, non-degenerate c. five-fold degenerate, five-fold degenerate D. non-degenerate, five-fold degenerate |
11 |
| 984 | Assertion A spectral line will be observed for ( 2 P_{z}-2 P_{y} ) transition Reason The energy of ( 2 P_{x} ) and ( 2 P_{y} ) orbitals is the same A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
11 |
| 985 | 0 | 11 |
| 986 | Summarise the rules for writing of distribution of electrons in various shells for the first eighteen elements. |
11 |
| 987 | Isotopes of iodine is used in the treatment of goiter. A. ( I-132 ) в. ( I-133 ) c. ( I-13 ) D. ( I-130 ) |
11 |
| 988 | I : Some alpha particles shot at a thin metal foil are reflected back toward the source. II : Alpha particles shot at thin metal foil sometimes approach the nuclei of the metal atoms head-on and arc thus repelled. |
11 |
| 989 | The shape of the orbital with the value of ( l=2, m=0 ) is : A. spherical B. double dumb-bell c. trigonal planar D. square planar |
11 |
| 990 | For which of the species, Bohrs theory is not applicable? ( mathbf{A} cdot B e^{+3} ) B. ( L i^{+2} ) ( mathbf{c} cdot H e^{+2} ) D. ( H ) |
11 |
| 991 | The electronic configuration of potassium is 2,8,8,1 and not 2,8,9 |
11 |
| 992 | An atom of an element has two electrons in the M shell. Identify its atomic number. A . 10 B. 12 ( c cdot 14 ) D. 15 |
11 |
| 993 | What is the effect on specific charge if the speed of electron increases? A. Decreases B. Increases c. Remains same D. None |
11 |
| 994 | The uncertainty in the position of an electron ( left(text { mass }=mathbf{9 . 1} times mathbf{1 0}^{-mathbf{2 8}} mathbf{g}right) ) moving with a velocity of ( 3.0 times ) ( 10^{4} c m^{-1} ) accurate up to ( 0.011 %, ) will be: A . ( 1.92 mathrm{cm} ) B. 7.68 ст c. ( 0.175 mathrm{cm} ) D. ( 3.84 mathrm{cm} ) |
11 |
| 995 | The band spectrum is caused by: A . molecules B. atoms c. any substance in solid state D. any substance in liquid state |
11 |
| 996 | The Schrodinger wave equation for hydrogen atom is: ( mathbf{Psi}_{2 s}=frac{1}{4 sqrt{2} pi}left(frac{1}{a_{0}}right)^{3 / 2}left[2-frac{r_{0}}{a_{0}}right] e^{-r / a_{0}} ) where ( a_{0} ) is Bohr radius. If the radial node in ( 2 s ) be at ( r_{0}, ) then find ( r ) in terms of ( a_{0} ) A ( cdot frac{a_{0}}{2} ) В. ( 2 a_{0} ) c. ( sqrt{2} a_{0} ) D. ( frac{a_{0}}{sqrt{2}} ) |
11 |
| 997 | Which is the correct relationship between wavelength and momentum of particles? A ( cdot lambda=frac{h}{p} ) B. ( pi=frac{h}{p} ) c. ( p=frac{lambda}{h} ) D. ( h=frac{P}{lambda} ) |
11 |
| 998 | In which of the following pairs do the two species resemble each other closely in chemical properties? A ( cdot frac{1}{1} H ) and ( _{1}^{2} H ) B. ( _{8}^{16} O ) and ( _{8}^{16} O^{2-} ) C ( cdot frac{24}{12} M g ) and ( _{12}^{24} M g^{2+} ) D. ( frac{14}{7} N ) and ( frac{14}{7} N^{3}- ) |
11 |
| 999 | Which of the following quantities will be zero for alpha particles at the point of closest approach to the gold atom in Rutherford’s scattering of alpha particles? A. Acceleration B. Kinetic energy c. Potential energy D. Electrical energy |
11 |
| 1000 | Q8. In a hydrogen atom, the energy of an electron in first Bohr’s orbit is 13.12 10° mol-. What is the energy required for its excitation to Bohr’s second orbit? . |
11 |
| 1001 | Q14. An electron beam after hitting a neutral crystal produces a diffraction pattern? What do you conclude? |
11 |
| 1002 | Penetration power of proton is A. more than electron B. less than electron C. equal to electron D. none of these |
11 |
| 1003 | An atom has mass number 23 and atomic number 11. How many protons, electrons and neutrons are present in the atom? A. 11,12,13 B. 11,11,12 c. 11,11,13 D. 11,14,15 |
11 |
| 1004 | The orbital angular momentum and angular momentum (classical analogue) for the electron of ( 4 s ) -orbita are respectively, equal to: A ( cdot sqrt{12} frac{h}{2 pi} ) and ( frac{h}{2 pi} ) B. zero and ( frac{2 h}{pi} ) c. ( sqrt{6} h ) and ( frac{2 h}{pi} ) D. ( sqrt{2} frac{h}{2 pi} ) and ( frac{3 h}{2 pi} ) |
11 |
| 1005 | The maximum kinetic energy of electron emitted in the photoelectric effect linearly depends on the of the incident radiations. A. temperature B. amplitude c. number D. frequency |
11 |
| 1006 | Atomic number of strontium ( (S r) ) is equal to: A . 28 B. 38 ( c cdot 42 ) D. 34 |
11 |
| 1007 | The average binding energy per nucleon is maximum for the nucleus: ( mathbf{A} cdot_{2} H e^{4} ) B ( cdot_{8} O^{16} ) ( mathbf{c} cdot_{26} F e^{56} ) D・ ( _{92} U^{238} ) |
11 |
| 1008 | A bulb of ( 40 mathrm{W} ) is producing a light of wavelength ( 620 mathrm{nm} ) with ( 80 % ) of efficiency, then the number of photons emitted by the bulb in 20 seconds are ( left.mathbf{1} e boldsymbol{V}=mathbf{1 . 6} times mathbf{1 0}^{-mathbf{1 9}} mathbf{J}, boldsymbol{h} boldsymbol{c}=mathbf{1 2 4 0 0} e boldsymbol{V}right) ) ( mathbf{A} cdot 2 times 10^{18} ) B . ( 10^{18} ) c. ( 10^{21} ) D. ( 2 times 10^{11} ) |
11 |
| 1009 | Maximum number of electrons in a sub shell is given by: A ( cdot(2 l+1) ) B. ( 2(2 l+1) ) ( mathbf{c} cdot(2 l+1)^{2} ) D. ( 2(2 l+1)^{2} ) |
11 |
| 1010 | 53. If the K, radiation of Mo (Z = 42) has a wavelength of 0.71 Å find the wavelength of the corresponding radiation of Cu (Z = 29) (a) 1 (b) 2 Å (c) 1.52 Å (d) 1.25 Å |
11 |
| 1011 | Which of the following pairs represents isobars? A ( cdot 2^{3} mathrm{He} ) and ( _{2}^{4} mathrm{He} ) B ( cdot frac{24}{12} mathrm{Mg} ) and ( _{12}^{25} mathrm{Mg} ) ( mathbf{c} cdot_{19}^{40} K operatorname{and}_{20}^{40} C a ) |
11 |
| 1012 | Which of the following configurations corresponds to element of highest ionisation energy? A ( cdot 1 s^{2}, 2 s^{1} ) B . ( 1 s^{2}, 2 s^{2}, 2 p^{3} ) C. ( 1 s^{2}, 2 s^{2}, 2 p^{2} ) D. ( 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{1} ) |
11 |
| 1013 | 4. Magnetic moment due to the motion of the electron in nth energy of hydrogen atom is proportional to (a) n (b) nº (c) n (d) n? |
11 |
| 1014 | Cathode rays have: A. mass only B. charge only c. no mass and no charge D. mass and charge both |
11 |
| 1015 | What is the distance of closest approach to the nucleus of an ( alpha ) particle which undergoes scattering by ( 180^{circ} ) in Geiger-Marsden experiment? |
11 |
| 1016 | Match List 1 with List 2: | 11 |
| 1017 | Filling the blanks. Both elements and compounds are substances. | 11 |
| 1018 | A negatively charged particle called Negatron was discovered. In the Millikan’s oil-drop experiment, the charges of the oil-drops in five experiments are reported as ( 3.2 times ) ( 10^{-19} ) coulomb; ( 4.8 times 10^{-19} ) coulomb ( 6.4 times 10^{-19} ) coulomb |
11 |
| 1019 | The cathode rays tube experiments carried out by J.J. Thomson demonstrated that: A. ratio of charge to-mass for the particles of the cathode rays varies as different gases are placed in the tube B. the mass of an atom is essentially all contained in its very small nucleus. C. cathode rays are streams of negatively charged ions. D. the charge-to-mass ratio for an electron is same for all gases. |
11 |
| 1020 | What is the total value of ( m ) for all electrons in ( mathrm{N} ) atom? |
11 |
| 1021 | ( M^{-2} ) configure is ( 1 s^{2} 2 s^{2} 2 p^{6}, ) then ( M^{+2} ) configuration will be : A ( cdot 1 s^{2} ) B. ( 1 s^{2} 2 s^{2} ) C ( cdot 1 s^{2} 2 s^{2} 2 p^{2} ) D. ( 1 s^{2} 2 s^{2} 2 p^{4} ) |
11 |
| 1022 | How long would it take a radio-wave of frequency, ( 6 times 10^{3} ) sec ( ^{-1} ) to travel from Mars to the Earth, a distance of ( 8 times ) ( 10^{7} k m ) |
11 |
| 1023 | ( 18 A r^{40} ) and ( _{19} K^{40} ) are a pair of A. isomers B. isobars c. isotopes D. isotones |
11 |
| 1024 | An element has 8 electrons in ( 4 d- ) subshell. Show the distribution of 8 electrons in the ( d ) -orbitals of the element within small rectangles. |
11 |
| 1025 | J.J. Thomson found that: A. Electron have negligible mass B. It have one unit of negative charge c. Option A and B both D. None of the above |
11 |
| 1026 | If an electron is travelling at ( 200 m / s ) within 1 m/ ( s ) uncertainty, what is the theoretical uncertainty in its position in ( mu m(text { micrometer }) ? ) A . 14.5 B . 29 c. 58 D. 114 |
11 |
| 1027 | The number of photons emitted in 10 hours by a ( 60 mathrm{W} ) sodium lamp are: (take ( lambda ) of photon ( =6000 mathrm{A}, h c=12400 ) eVA, ( h= ) Planck’s constant, ( c= ) speed of light) A ( cdot 6.50 times 10^{24} ) B. ( 6.40 times 10^{23} ) c. ( 8.40 times 10^{23} ) 3 D. 3.40 ( times 10^{23} ) |
11 |
| 1028 | Which of the following species are expected to have spectrum similar to hydrogen? This question has multiple correct options A ( . H e^{+} ) B. ( H e^{2+} ) ( c cdot L i^{2} ) ( mathbf{D} cdot L i^{+} ) |
11 |
| 1029 | If an electron is moving with a velocity of ( 1.1 times 10^{6} mathrm{ms}^{-1} ) de broglie wave length approximately is: A ( cdot 4.1 times 10^{-11} mathrm{m} ) В . ( 4.9 times 10^{-9} mathrm{m} ) c. ( 7 times 10^{-10} m ) D. ( 3.306 times 10^{-8} mathrm{m} ) |
11 |
| 1030 | Assertion The mass number of hydrogen is equal to its atomic number Reason H-atom has no neutrons A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
11 |
| 1031 | Number of angular nodes for ( 4 d ) orbital is A . 4 B. 3 ( c cdot 2 ) ( D ) |
11 |
| 1032 | An electron, practically at rest, is initially accelerated through a potential difference of 100 volts. It then has a de Broglie wavelength ( =lambda_{1} A . ) It then get retarded through 19 volts and then has a wavelength ( lambda_{2} ). A further retardation through 32 volts changes the wavelength to ( lambda_{3} A, ) what is ( frac{lambda_{3}-lambda_{1}}{lambda_{1}} ? ) |
11 |
| 1033 | Select the correct option. (a) Energy of ground state of ( boldsymbol{H} e^{+} ) [ (i)+6.04 e v ] (b) Potential energy of I orbit of ( boldsymbol{H}- ) atom (ii) -27.2 eV (c) Kinetic energy of II excited state of ( boldsymbol{H} e^{+} ) (iii) +54.4 ev (d) Ionisation potential of ( boldsymbol{H} boldsymbol{e}^{+} ) (iv) ( -54.4 mathrm{eV} ) ( A cdot a(i), b ) (ii) ( , c ) (iii), d (iv) B. a (iv), b (iii), c (ii), d(i) ( c cdot a(i v), b(i i), c(i), d ) (iii) D. a (ii), b (iii), c (i), d (iv) |
11 |
| 1034 | For ( n=3 ) energy level, number of orbitals of all kind that are possible is: A . 9 B. 7 ( c cdot 8 ) D. 10 |
11 |
| 1035 | Who said that cathode rays consist of negatively charged particles? A. Dalton B. Rutherford c. James chadwick D. J.J. Thomson |
11 |
| 1036 | How will you find out the maximum number of electrons in the main energy level? A . ( n ) B. ( n^{2} ) ( c cdot 2 n^{4} ) D. ( 2 n^{2} ) |
11 |
| 1037 | Calculate the wavelength for the emission transition if it starts from the orbit having radius ( 1.3225 mathrm{nm} ) and ends at ( 211.6 mathrm{pm} . ) Name the series to which this transition belongs and the region of the spectrum. |
11 |
| 1038 | Calculate the wavelength of an electron moving with a kinetic energy of ( 18.62 times 10^{-25} J ) |
11 |
| 1039 | Match the items in List 1 with those in List 2 |
11 |
| 1040 | Who was the first scientist to propose a model for the structure of an atom? A. J.J. Thomson B. Dalton c. Ernest Rutherford D. E. Goldstein |
11 |
| 1041 | If uncertainties in the measurement of position and momentum of an electron are equal, calculate uncertainty in the measurement of velocity. |
11 |
| 1042 | When an electron in hydrogen spectrum jumps from ( n=7 ) to ( n=2 ), the total number of spectral lines possible are: A . 21 B . 15 ( c .5 ) D. |
11 |
| 1043 | Light travels with a speed of ( 3 times 10^{8} ) ( {m s} wedge{-1} . ) The distance travelled by light in 1 femto second is: A. ( 0.03 mathrm{mm} ) B. ( 0.003 m m ) ( mathbf{c} .3 m m ) D. ( 0.0003 mathrm{mm} ) |
11 |
| 1044 | Which is correct with respect to ‘p’ orbitals? A. They are spherical B. They have a strong directional character c. They are five fold degenerate D. They have no directional character |
11 |
| 1045 | The aufbau principle is violated in ( 2 s ) [ 2 p x quad 2 p y quad 2 p z ] This question has multiple correct options ( mathbf{A} ) ( uparrow downarrow quad uparrow downarrow ) B. ( uparrow ) ( uparrow downarrow ) [ uparrow ] c. ( uparrow downarrow ) ( uparrow ) ( uparrow ) D. ( uparrow downarrow quad uparrow downarrow ) |
11 |
| 1046 | Atomic number of nitrogen is ( 7 . ) The number of protons in Nitrogen atom is equal to ( A cdot 14 ) B. 7 ( c cdot 2 ) D. 15 |
11 |
| 1047 | The carbonate of a metal is isomorphous (similar formula) with magnesium carbonate and contains 6.091 percent of carbon. The atomic weight of metal is: A . 24 B. 56 ( c cdot 137 ) D. 260 |
11 |
| 1048 | When a hydrogen sample in the ground state is bombarded then what potential is required to accelerate electron so that first Paschen line is emitted, then calculate the energy difference? A . 2.55 B. 0.65 c. 12.09 D. 12.75 |
11 |
| 1049 | According to JJ Thomson’s atomic model, negative charges are embedded in: A. A lump of positive charge B. A lump of neutral particles c. A lump of small atoms D. The nucleus |
11 |
| 1050 | A neutron breaks into a proton and an electron. This decay of neutron is accompanied by the release of energy. Assuming that ( 50 % ) of the energy is produced in the form of electromagnetic radiation, what will be the frequency of radiation produced. Will this photon be sufficient to cause ionization of aluminum? In case it is able to do so what will be the energy of the electron ejected from the aluminum atom ( boldsymbol{I} boldsymbol{E}_{1} ) of ( boldsymbol{A l}=mathbf{5 7 7} mathrm{KJ} / mathrm{mol} ) |
11 |
| 1051 | Members of which of the following have similar chemical properties? A. Isotope B. Isobars c. Allotropes D. Both isotopes and allotropes |
11 |
| 1052 | According to Bohr’s theory of hydrogen atom, which of the following is quantized for an electron? A. Acceleration B. Velocity c. Angular momentum D. Angular acceleration |
11 |
| 1053 | An atom with the same number of protons but a different number of neutrons is : A . a molecule B. a mixture of compound c. an isotope D. an isomer E. an acid salt |
11 |
| 1054 | a) Assign the position of the element having outer electronic configuration in the periodic table (i) ( n s^{2} n p^{4} ) for ( n=3 ) ( (n-1) d^{2} n s^{2} ) for ( n=4 ) b) The size of ( N a^{+} ) cation is smaller than ( N a . ) Explain |
11 |
| 1055 | Dalton’s atomic theory was not accepted fully: A. when atoms combine It must be presumed to be a binary one, unless some cause appear to the contrary. B. when elements react, their atoms sometimes combine in more than one simple, whole-number ratio. C. elements are characterized by the mass of their atoms. D. None of the above |
11 |
| 1056 | electron of hydrogen atom in a spherical shell of infinitesimal thickness ( d r, ) at a distance r from the nucleus. The volume of this shell is ( 4 pi r^{2} d r . ) The qualitative sketch of the dependence of P on r is: ( mathbf{A} ) B. ( c ) D. |
11 |
| 1057 | Show that the circumference of the Bohr orbit for the hydrogen atom is an integral multiple the de-Broglie wavelength associated with the electron revolving around orbit. |
11 |
| 1058 | Neutron was discovered by: A. J.J. Thomson B. Chadwick c. Rutherford D. Priestley |
11 |
| 1059 | 48. Let o ng and ac denote the wavelengths of the X-rays of the Ką Kg and La lines in the characteristic X-rays for a metal (a) nada >d; (b) da >d;> da 1 1 1 1 1 1 (d) = += == а в Ло (c) AB na na 2 TO V 1…. . |
11 |
| 1060 | An electron in a hydrogen atom in its ground state absorbs energy equal to the ionization energy of ( L i^{+2} . ) The wavelength of the emitted electron is: A. ( 3.32 times 10^{-10} mathrm{m} ) в. 1.17 А c. ( 2.32 times 10^{-9} mathrm{nm} ) D. 3.33 pm |
11 |
| 1061 | What is the energy associated with ( 3^{r d} ) energy shell of hydrogen atom? В. ( -0.342 times 10^{-19} mathrm{J} ) c. ( -0.126 times 10^{-19} mathrm{J} ) D. ( -2.41 times 10^{-19} mathrm{J} ) |
11 |
| 1062 | 23. Let the potential energy of a hydrogen atom in the state be zero. Then, its energy in the first excited State be (a) 10.2 eV (b) 13.6 eV (c) 23.8 eV (d) 27.2 eV |
11 |
| 1063 | Give reason for the following: The mass number of an atom is slightly less than the actual atomic mass. |
11 |
| 1064 | The values of Planck’s constant is ( 6.63 times 10^{-34} J s . ) The velocity of light is ( 3.0 times 10^{8} m s^{-1} . ) Which value is closest to the wavelength in nanometres of a quantum of light which frequency of ( 8 times 10^{15} s^{-1} ? ) ( mathbf{A} cdot 5 times 10^{-18} ) B. ( 4 times 10^{1} ) ( c cdot 3 times 10^{7} ) D. ( 2 times 10^{-25} ) |
11 |
| 1065 | Assume that the potential energy of a hydrogen atom in its ground state is zero. Then its total energy in the first excited state will be: A . ( 13.6 e V ) в. 27.2eV c. ( 23.8 e V ) D. ( 10.2 e V ) |
11 |
| 1066 | If an electron is moving with velocity ( 500 m s^{-1}, ) which is accurate up to ( 0.005 % ) then calculate uncertainty in its position. ( left[boldsymbol{h}=mathbf{6 . 6 3} times mathbf{1 0}^{-mathbf{3 4}} boldsymbol{J}-right. ) ( s, ) mass of electron ( =9.1 times ) ( left.mathbf{1 0}^{-mathbf{3 1}} quad boldsymbol{K} boldsymbol{g}right] ) |
11 |
| 1067 | ( 1^{s t} ) excitation potential for the ( mathrm{H}- ) like(hypothetical)sample is 24V. Choose the correct statement. This question has multiple correct options A ( cdot 1^{s t} ) excitation potential for the ( mathrm{H} ) like(hypothetical)sample is 24v B. Ionisation energy of the sample is 32 ev C. Binding energy of ( 3^{r d} ) excited state is 2 ev D. ( 2^{text {nd }} ) excitation potential of the sample is ( frac{32 times 8}{9} V ) |
11 |
| 1068 | 2 1 2 21. Electrons are accelerated in television tubes through potential differences of about 10 kV. The highest frequency of the electromagnetic waves emitted when these electrons strike the screen of the tube is (a) 2.4 x 1018 Hz (b) 3.6 x 1018 Hz (c) 2.2 x 1017 Hz (d) 3.2 x 1016 Hz |
11 |
| 1069 | Energy of H- atom in the ground state is ( -13.6, ) Hence energy in the second excited state is: A . -6.8ev B. – 3.4ev c. -1.51ev D. -4.3ev |
11 |
| 1070 | Q3. What are degenerate orbitals? | 11 |
| 1071 | The mass number of an atom is the sum of the number of protons and number of neutrons in an atom. If it is true enter 1 else 0 |
11 |
| 1072 | Energy of electron in first excited state of ( H ) -atom is: A. ( -13.12 times 10^{5} mathrm{J} / mathrm{mol} ) B. ( -3.28 times 10^{5} mathrm{J} / mathrm{mol} ) c. ( 13.12 times 10^{3} J / ) mol D. ( 3.28 times 10^{2} J / ) mol |
11 |
| 1073 | In Thomson’s plum-pudding model, electrons are not: A. negatively charged B. present in every type of atom C . collected together in the center of the atom D. scattered throughout a blob of positively charged material |
11 |
| 1074 | An atom of an element has 3 electrons in ( 4 p ) subshell. The atomic number of the element is : A . 31 B. 33 c. 35 D. 34 |
11 |
| 1075 | Which of the following is not the basic postulate(s) of Dalton’s atomic theory? A. Atoms are neither created nor destroyed in a chemical reaction B. In a compound, the relative number and kinds of atom are constant c. Atoms of all elements are alike, including their masses D. Each element is composed of extremely small particles called atoms |
11 |
| 1076 | Which of the properties of isotopes of an element is different? A. First ionisation enthalpy B. Effective nuclear charge c. Electron affinity D. Melting point and boiling point |
11 |
| 1077 | The element having electronic configuration. ( [boldsymbol{K} boldsymbol{r}] boldsymbol{4} boldsymbol{d}^{10} boldsymbol{4} boldsymbol{f}^{14} boldsymbol{5} boldsymbol{s}^{2} boldsymbol{5} boldsymbol{p}^{6} boldsymbol{5} boldsymbol{f}^{2} boldsymbol{6} boldsymbol{s}^{2} ) belongs to A. s-block B. p-block c. d-block D. f-block |
11 |
| 1078 | The binding energy of electrons in a metal is ( 193 mathrm{kJ} mathrm{mol}^{-1} ). The threshold frequency of the metal is: A. ( 8.83 times 10^{14} mathrm{s}^{-1} ) B. 4.83 ( times 10^{14} mathrm{s}^{-1} ) c. ( 5.83 times 10^{14} mathrm{s}^{-1} ) D. 6.83 ( times 10^{14} mathrm{s}^{-1} ) |
11 |
| 1079 | The probability of finding the electron in ( boldsymbol{p}_{boldsymbol{x}} ) -orbital is: This question has multiple correct options A. maximum on two opposite sides of the nucleus along ( x ) -axis B. zero at the nucleus c. same on all the sides around the nucleus D. zero on the ( z ) -axis |
11 |
| 1080 | ( mathbf{2} boldsymbol{s} stackrel{I}{rightarrow} mathbf{2} boldsymbol{p} stackrel{I I}{rightarrow} mathbf{3} boldsymbol{d} stackrel{I I}{rightarrow} mathbf{3} boldsymbol{p} stackrel{I V}{rightarrow} mathbf{4} boldsymbol{s} stackrel{boldsymbol{V}}{rightarrow} mathbf{2} boldsymbol{p} ) The electronic transitions show above are observed when lithium atoms are sprayed into a hot flame. The various transitions are numbered for identification. Which of these transitions would result in emission of electromagnetic radiation (light)? A. I and II only B. I and III only c. I and v only D. III and IV only E. III and v only |
11 |
| 1081 | The mass of an electron is ( 9.1 times 10^{-31} mathrm{kg} ) If its kinetic energy is ( 3.0 times 10^{-25} mathrm{J} ) calculate its wave length. |
11 |
| 1082 | Calculate the number of revolutions/sec around the nucleus of an electron placed in III orbit of ( boldsymbol{H} ) -atom A ( cdot 1.44 times 10^{12} ) B . ( 7.29 times 10^{7} ) c. ( 15.33 times 10^{14} ) D. ( 2.44 times 10^{14} ) |
11 |
| 1083 | Assertion Atom is electrically neutral Reason A neutral particle, neutron is present in the nucleus of the atom A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 1084 | Electromagnetic radiation of wavelength ( 242 mathrm{nm} ) is just sufficient to ionise the sodium atom. What should be ionization energy of sodium atom in order of ( 10^{-19} ?left(c=3 times 10^{8} mathrm{ms}^{-1}, h=right. ) ( 6.626 times 10^{-34} mathrm{Js} ) A . 8.2 B. 8 c. 9 D. 9.2 |
11 |
| 1085 | The value of Bohr radius for hydrogen atom is: A ( .0 .529 times 10^{-8} mathrm{cm} ) B . ( 0.529 times 10^{-10} mathrm{cm} ) c. ( 0.529 times 10^{-6} mathrm{cm} ) D. ( 0.529 times 10^{-12} mathrm{cm} ) |
11 |
| 1086 | An electron in a Bohr orbit of a hydrogen atom with the quantum number ( n_{2} ) has an angular momentum ( 4.2176 times ) ( 10^{-34} k g m^{2} s^{-1} . ) If electron drops from this level to the next lower level, then the wavelength of this line is: A ( cdot 18.75 times 10^{-7} m ) B. ( 1.87 times 10^{-7} mathrm{m} ) c. ( 187.5 times 10^{-7} mathrm{m} ) D. ( 0.187 times 10^{-7} m ) |
11 |
| 1087 | 32. The ratio between total acceleration of the electron in singly ionized helium atom and hydrogen atom (both in ground state) is (a) 1 . (b) 8 (c) 4 (d) 16 |
11 |
| 1088 | Q. 39 Table-tennis ball has mass 10 g and speed of 90 m/s. It spee measured within an accuracy of 4%, what will be the uncertainty in speed and position? |
11 |
| 1089 | State True or False. Gamma rays produce maximum ionization in gases. A. True B. False |
11 |
| 1090 | Which of the following species has less number of protons than the number of neutrons? This question has multiple correct options A ( cdot frac{12}{6} C ) В . ( _{9}^{9} F ) ( mathbf{c} cdot_{11}^{23} N a ) D ( cdot frac{24}{12} M g ) |
11 |
| 1091 | Calculate the wave number of the highest energy transition in the Balmer series of the hydrogen atom: ( left[boldsymbol{R}_{boldsymbol{H}}=mathbf{1 0 9 6 7 8 c m}^{-1}right] ) A ( .27419 .5 mathrm{cm}^{-1} ) В. 2741.95 ( c m^{-1} ) c. ( 274.195 mathrm{cm}^{-1} ) D. 274195.1 ( c m^{-} ) |
11 |
| 1092 | Consider the following statements and predict the wrong statement(s) a. Half filled and fully filled orbitals have greater stability due to greater exchange energy and symmetrical distribution b. The energy of ( 3 s ) orbital is less than ( 3 p ) orbital for hydrogen atom. c. The uncertainty principle is ( Delta boldsymbol{E} times ) ( Delta t leq frac{h}{4 pi} ) ( boldsymbol{d} boldsymbol{E}=-boldsymbol{2} . boldsymbol{1} boldsymbol{7} boldsymbol{8} times boldsymbol{1} boldsymbol{0}^{-18}left(frac{boldsymbol{Z}^{2}}{boldsymbol{n}^{2}}right) boldsymbol{J} boldsymbol{a t o m}^{-1} ) can be used to calculate the change in energy when the electron changes orbit in H-atom A. b and conly B. b, c and donly c. a and b only D. a and donly |
11 |
| 1093 | A proton is accelerated to one-tenth of the velocity of light. If its velocity can be measured with a precision ( pm 1 % ), then its uncertainty in position is: A ( cdot 1.05 times 10^{-13} m ) В. ( 1.13 times 10^{-13} mathrm{m} ) c. ( 1.15 times 10^{-13} mathrm{m} ) D. ( 1.25 times 10^{-13} mathrm{m} ) |
11 |
| 1094 | Which of the following statements are correct for an electron that has ( n=4 ) and ( m=-2 ? ) This question has multiple correct options A. The electron may be in a ( d ) -orbital B. The electron is in the ( 3^{r d} ) -orbital C . The electron may be in a ( p ) -orbital D. The electron must have the spin quantum number ( = ) ( 1 / 2 ) |
11 |
| 1095 | Carbon-dating uses carbon isotope with number of neutrons eight if true enter 1 , else enter 0 |
11 |
| 1096 | The net charge inside an atom is zero because: A. the magnitude of positive charge is more than negative charge inside atom B. the magnitude of positive and negative charge is same inside atom C. the magnitude of positive and negative charge is same outside atom D. the magnitude of positive charge is less than negative charge inside atom |
11 |
| 1097 | 28. The ratio of maximum to minimum possible radiation energy in Bohr’s hypothetical hydrogen atom is equal to (a) 2 (b) 4 (c) 4/3 (d) 3/2 |
11 |
| 1098 | The ( t_{1 / 2} ) for ( ^{14} mathbf{C} ) in (i) ( ^{14} mathrm{CO}_{2} ) (ii) ( ^{14} C_{6} mathbf{H}_{12} mathrm{O}_{6}(text { iii }) ) coal containing ( ^{14} mathbf{C}(i boldsymbol{v}) ) cellulose containing ( ^{14} mathbf{C} ) is : ( mathbf{A} cdot operatorname{more} operatorname{in}^{14} mathrm{CO}_{2} ) B. more in coal containing ( ^{14} mathrm{C} ) c. more in ( ^{14} C_{6} mathrm{H}_{12} mathrm{O}_{6} ) D. same in all species |
11 |
| 1099 | Which of the following is true regarding an ( N e ) atoms with a mass number of 20 and ( O^{2-} ) ion with a mass number of ( 16 ? ) A. They contain the same number of protons B. They contain the same number of neutrons C. They contain the same number of protons plus netrons D. The are isoelectronic E. They are isomers |
11 |
| 1100 | A sample of ( H e^{+} ) ions in a gaseous state had all ions in ( n^{t h} ) excited state. This sample on returning to ground state emits a total of 28 spectral lines. Value of ( n ) is: ( A cdot 8 ) B. 7 ( c cdot 6 ) D. 5 |
11 |
| 1101 | In which region of electromagnetic spectrum does the Balmer series lie? A. UV B. Visible c. Infrared D. Far infrared |
11 |
| 1102 | Elements are characterized by the of their atoms. A. electrons B. mass c. protons D. shape |
11 |
| 1103 | The de-Broglie wavelength associated with a material particle is : A. directly proportional to its energy B. directly proportional to momentum C. inversely proportional to its energy D. inversely proportional to momentum |
11 |
| 1104 | Bohr’s theory is not applicable to: This question has multiple correct options A. He B . ( L i^{2} ) ( mathrm{c} cdot mathrm{He}^{2} ) D. the H-atom |
11 |
| 1105 | Which of the following set of quantum number represents highest energy of an atom? ( A cdot_{n=3, mid=2, m=1, s=+frac{1}{2}} ) B. ( n=3,1=2, m=1, s=-frac{1}{2} ) ( c cdot_{n=4,1=0, m=0, s=+frac{1}{2}} ) D. ( n=3, s=+frac{1}{2} ) |
11 |
| 1106 | What is shortest wavelength line in the Paschen series of ( L i^{2+} ) ion? |
11 |
| 1107 | The total number of orbitals in the fifth energy level is: A . 5 B. 10 c. 18 D. 25 |
11 |
| 1108 | If radius of ( 3^{r d} ) orbit of ( L i^{2+} ) ion is ‘x’ ( mathrm{cm} ) then de-broglie wavelength of electrons in the ( 1^{s t} ) orbit is : ( A cdot frac{2 pi x}{3} mathrm{cm} ) в. ( 6 pi x ) ст c. ( 3 pi x ) ст D. ( frac{2 pi x}{6} mathrm{cm} ) |
11 |
| 1109 | Calculate the radius of first orbit in ( H e^{+} ) ion. A ( cdot 0.2645 A^{circ} ) B . 26.45 A ( ^{text {о }} ) c. ( 0.2465 times 10^{-12} ) D. none of these |
11 |
| 1110 | A ( 3 p ) -orbital has: A. two non-spherical nodes. B. two spherical nodes. C . one spherical and one non-spherical node. D. one spherical and two non-spherical nodes. |
11 |
| 1111 | Determine the ratio of charge to mass (specific charge) for electron and alpha particle. A .2: B. 1: 1 c. 1: 2 D. None of these |
11 |
| 1112 | The number of occupied sub-shell in ( mathrm{Cr} ) ( + ) is : A . 3 B. 4 ( c cdot 7 ) D. 6 |
11 |
| 1113 | The effective atomic number of Mn,in ( M n_{2}(C O)_{10} ) is A . 36 B. 38 ( c cdot 32 ) D. 34 |
11 |
| 1114 | Heisenberg uncertainty principle is not valid for : This question has multiple correct options A. moving electrons B. motor car c. stationary particles D. all of the above |
11 |
| 1115 | In an atom, the differentiating electron enters into 7 s sub shell. The number of incomplete shells in the atom could be: A . 1 B . 2 ( c .3 ) D. |
11 |
| 1116 | Write electronic configurations of the elements (number in the brackets indicate atomic numbers) potassium ( (mathbf{1 9}) ) |
11 |
| 1117 | What are the characteristics of isobars? A. They have different atomic numbers. B. They have same electronic configuration. C. They have same number of neutrons. D. All of the above |
11 |
| 1118 | In a hydrogen atom, the energy of an electron in an orbit is -3.4 eV. When it is excited to the next higher energy level and comes back to ground state, calculate the wave length of emitted radiation. ( mathbf{A} cdot 9 times 10^{-7} m ) В. ( 9 times 10^{-9} m ) ( mathbf{c} cdot 9 A^{circ} ) D. none of these |
11 |
| 1119 | No. of wave in third Bohr’s orbit of hydrogen is |
11 |
| 1120 | In which energy level is the outer electron in rubidium located? A . 85 B. 2 c. 37 ( D ) ( E .5 ) |
11 |
| 1121 | Analyze the Photoelectron Spectra. What is the identity of the element? ( A cdot H ) в. ( H e ) ( c cdot L i ) D. ( B e ) |
11 |
| 1122 | A dust particle has mass equal to ( 10^{-11} g, ) diameter ( 10^{-4} c m ) and velocity ( 10^{-4} mathrm{cm} / mathrm{s} . ) The error in measurement of velocity is ( 0.1 % . ) What will be the uncertainty in its position? A ( cdot 0.527 times 10^{10} mathrm{cm} ) B. ( 5.27 times 10^{9} mathrm{cm} ) c. ( 0.527 times 10^{-15} mathrm{cm} ) D. ( 0.527 times 10^{-9} mathrm{cm} ) |
11 |
| 1123 | said that cathode rays consist of negatively charged particles and these were named as electrons. A . Goldstein B. Thomson c. chadwick D. Rutherford |
11 |
| 1124 | From Bohr’s model radius of the orbit and energy of the hydrogen atom are calculated as: This question has multiple correct options A. radius of the 1st orbit is ( 0.529 A^{circ} ) B. energy of the 1st orbit is ( -13.6 e V ) C. energy of the 1st orbit is ( -21.72 times 10^{-19} mathrm{J} ) D. radius of the 1st orbit is ( 1.06 A^{circ} ) |
11 |
| 1125 | In which of the following process highest energy is absorbed? ( mathbf{A} cdot C u rightarrow C u^{+} ) в. ( B r rightarrow B r^{-} ) c. ( I rightarrow I^{-} ) D. ( L i rightarrow L i^{+} ) |
11 |
| 1126 | The threshold wavelength for ejection of an electron from metal is 310 nm. The kinetic energy of emitted photoelectron is ( 36 times 10^{-20} J . ) Then the frequency of incident light is: A ( cdot 1.5 times 10^{15} mathrm{Hz} ) B . ( 2.5 times 10^{18} mathrm{Hz} ) c. ( 1 times 10^{22} H z ) D. 2.5 ( times 10^{12} mathrm{Hz} ) |
11 |
| 1127 | The number of neutrons in the parent nucleus which gives ( ^{14} mathrm{N} ) on beta emission is |
11 |
| 1128 | 33. Hydrogen atoms are excited from ground state to the state of principal quantum number 4. Then, the number of spectral lines observed will be (a) 3 (b) 6 (C) 5 (d) 2 |
11 |
| 1129 | The photoelectric effect of Ba consists of emission of electrons from its ionisation energy on irradiation with light from the ionization energy of ( boldsymbol{H} e- ) atom is irradiation with light. A photon with a minimum energy of ( 3.97 times ) ( 10^{-19} J ) is necessary to eject electron from Ba. (a)What is the frequency of radiation corresponding to this value? (b) Will a blue light of wavelength ( 450 n m ) be able to eject at electron from Ba? (Given ( h=6.626 times 10^{-27} ) erg ( – ) ( boldsymbol{s} boldsymbol{e} boldsymbol{c} ) ( mathbf{A} cdot 6 times 10^{13} H z, ) yes B. ( 6 times 10^{13} H z ), no C ( .5 .99 times 10^{14} mathrm{Hz} ), yes D. ( 3.6 times 10^{13} mathrm{Hz} ), no |
11 |
| 1130 | When ( alpha ) -particles are sent through a thin metal foil, most of them go straight through the foil because: This question has multiple correct options A. ( alpha ) – particles are much heavier than electrons B. ( alpha ) -particles are positively charged c. most part of the atom is empty space D. ( alpha ) -particles move with high speed |
11 |
| 1131 | Suppose the elements ( X ) and ( Y ) combine to form two compounds ( boldsymbol{X} boldsymbol{Y}_{2} ) and ( X_{3} Y_{2} . ) When 0.1 mole of ( X Y_{2} ) weighs ( 10 g ) and 0.05 mole of ( X_{3} Y_{2} ) weighs ( 9 g ), the atomic weights of ( X ) and ( boldsymbol{Y} ) are: |
11 |
| 1132 | 26. The radius of the Bohr orbit in the ground state of hydrogen atom is 0.5 Å. The radius of the orbit of the electron in the third excited state of He will be (a) 8 Å (b) 4 Å (c) 0.5 Å (d) 0.25 Å |
11 |
| 1133 | What is the name and symbol of the element with atomic number ( 112 ? ) A. Ununbium, Uub B. Unnilbium, Unb c. Ununnillum, uun D. Ununtrium, Uut |
11 |
| 1134 | Q. 23 Show the distribution of electrons in oxygen atom (atomic number 8) using orbital diagram. Ans. O = 15² 282 204 |
11 |
| 1135 | 19. The emission spectra is observed by the consequence of transition of electron from higher energy state to ground state of Het ion. Six different photons are observed during the emission spectra, then what will be minimum wavelength during transition? (a) 27 RH (b) 15 RH 15 16 (c) 16RA 15R, |
11 |
| 1136 | An electron is moving in 4 th orbit and its de-Broglie wavelength is ( lambda ). What is the circumference of the fourth orbit? ( A cdot 2 / lambda ) B. ( 2 lambda ) c. ( 4 lambda ) D. ( 4 / lambda ) |
11 |
| 1137 | From equaliomu n atom corresponding to ie. E< E p < Ec. If a liations corresponding to the 11. Energy levels A, B, C of a certain atom corres increasing values of energy i.e. EA <ER <E are the wavelengths of radiations correspondin transitions C to B, B to A and C to A, respective of the following statements is correct atom is drogen e atom (2) Az = 2 + 2 (6) dez- hth (d) z = x + 22 (c) , + 2y + 2z = 0 a 11 . 1 m |
11 |
| 1138 | ULI 2 U 10 ULULLLEE 39 Q43. An ion with mass number 37 possesses one unit of negative charge. If imber 37 possesses one unit of negative charge. If the ion contains 11.1% more neutrons than the electrons, find the symbol of the ion. 2 |
11 |
| 1139 | Total no. of electron in ( N a ) having ( n times ) ( ell=0 ) is : ( mathbf{A} cdot mathbf{5} ) B. 2 ( c cdot 6 ) D. 8 |
11 |
| 1140 | What is the name for the number of protons in an atom? A. Atomic identity B. Atomic mass c. Atomic weight D. Atomic number |
11 |
| 1141 | The discovery of proved that atom is divisible. |
11 |
| 1142 | 41. A stationary hydrogen atom of mass M emits a photon corresponding to the first line of Lyman series. If R is the Rydberg’s constant, the velocity that the atom acquires is 3 Rh Rh 4 M 4M (c) Rh an (d) Rh |
11 |
| 1143 | What would be the minimum uncertainty in de-Broglie wavelength of a moving electron accelerated by potential difference of 6 volt and whose uncertainty in position is ( frac{7}{22} n m ? ) A ( .6 .25 AA ) в. 6 А c. 0.625 , D. ( 0.3125 dot{A} ) |
11 |
| 1144 | 69. If potential energy between a proton and an electron is given by TU1 = ke’/2R”, where e is the charge of electron and R is the radius of atom, then radius of Bohr’s orbit is given by (h = Planck’s constant, k = constant) ke²m 60² ke²m 4x² ke²m 2n ke²m n n |
11 |
| 1145 | What is the ratio between the energies of two radiations one with a wavelength of ( 6000 A ) and other with 2000 A? |
11 |
| 1146 | Q.46 Match the following. Column 1 A. Photon B. Electron N- Column II 1. Value is 4 for N-shell 2. Probability density 3. Always positive value 4. Exhibits both momentum and wavelength w D. Principal quantum number n |
11 |
| 1147 | The predominant yellow line in the spectrum of a sodium vapour lamp has a wavelength of 590nm. What minimum accelerated potential is needed to excite this line in an electron tube having sodium vapours? A. 8.44 volt. B . 2.11 volt. c. 6.11 volt. D. 4.22 volt. |
11 |
| 1148 | The outermost electronic configuration of the most electronegative element is: ( mathbf{A} cdot n s^{2} n p^{3} ) В ( cdot n s^{2} n p^{4} ) c. ( n s^{2} n p^{5} ) D. ( n s^{2} n p^{6} ) |
11 |
| 1149 | An atom of an element has one electron in the valence shell and the two inner shells have 8 electrons each. Find the atomic number of that element. |
11 |
| 1150 | The ratio of the radii of the atom to the nucleus is : A ( cdot 10^{4}: 1 ) B . ( 10^{-4}: 1 ) ( mathrm{c} cdot 10^{2}: 1 ) D. ( 10^{3}: 1 ) |
11 |
| 1151 | Energy of the state ( S_{1} ) in units of the hydrogen atom ground state energy is: A. 0.75 B. 1.50 c. 2.25 D. 4.50 |
11 |
| 1152 | How many maximum electrons ( f ) subshell can accommodate? A . 12 B. 14 ( c cdot 8 ) D. 10 |
11 |
| 1153 | The maximum tendency to form unipositive ion is for the element which has the following electronic configuration: A ( cdot 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2} ) B . ( 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2}, 3 p^{1} ) c. ( 1 s^{2}, 2 s^{2}, 2 p^{6} ) D. ( 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2}, 3 p^{3} ) |
11 |
| 1154 | 13. The electron in a hydrogen atom makes a transition from an excited state to the ground state. Which of the following statements is true (a) Its kinetic energy increases and its potential and total energies decrease (b) Its kinetic energy decreases, potential energy increases and its total energy remains the same (c) Its kinetic and total energies decrease and its potential energy increases (d) Its kinetic, potential and total energies decreases |
11 |
| 1155 | The experiment which led to the discovery of nucleus was performed by : A. Goldstein B. J.J. Thomson c. Dalton D. Rutherford |
11 |
| 1156 | A proton and an ( alpha ) -particle are accelerated through the same potential difference. The ratio of their De Broglie wavelength is: A. ( sqrt{2} ) B. ( frac{1}{sqrt{2}} ) ( c cdot 2 sqrt{2} ) D. 2 |
11 |
| 1157 | In a certain electronic transition in the hydrogen atom from an initial state (1) to a final state (2), the difference in the orbital radius ( left(r_{1}-r_{2}right) ) is 24 times the first Bohr radius. Identify the transition: ( mathbf{A} cdot 5 rightarrow 1 ) B . ( 25 rightarrow 1 ) c. ( 8 rightarrow 3 ) D. ( 1 rightarrow 5 ) |
11 |
| 1158 | Which of the following is(are) matter? Chair, air, love, smell, hate, almonds, thought, cold, cold-drink, smell of perfume. |
11 |
| 1159 | What is the hybridization state of carbon number 2 and 3 in the following compound ( boldsymbol{C H}_{2}=boldsymbol{C H}-boldsymbol{C} equiv boldsymbol{C H} ) A. sp and ( s p^{2} ) B. ( s p^{2} ) and ( s p ) ( mathbf{c} cdot s p^{3} ) and ( s p ) D. ( s p ) and ( s p ) |
11 |
| 1160 | К) Тоос сороо 28. A metal surface is illuminated by a light of given intensity and frequency to cause photoemission. If the intensity of illumination is reduced to one-fourth of its original value, then the maximum KE of emitted photoelectrons will become (a) (1/16)th of original value (b) unchanged (c) twice the original value (d) four times the original value |
11 |
| 1161 | Which of the following arrangements of electrons is mostly likely to be stable? ( A ) begin{tabular}{|c|c|c|c|c|c|} hline( uparrow ) & ( uparrow ) & ( uparrow d ) & ( uparrow ) & ( uparrow ) & ( ^{4 s} ) \ hline end{tabular} в. begin{tabular}{|c|c|c|c|c|c|} hline( uparrow downarrow ) & ( uparrow ) & ( uparrow ) & ( uparrow ) & ( uparrow ) & ( uparrow ) \ hline end{tabular} ( c ) begin{tabular}{|c|c|c|c|c|} hline( uparrow ) & ( uparrow ) & ( uparrow ) & ( uparrow ) & ( uparrow ) \ hline end{tabular} ( frac{4}{downarrow} ) D. begin{tabular}{r} ( 4 s ) \ hline( uparrow uparrow ) end{tabular} begin{tabular}{|c|c|c|c|c|c|} hline( uparrow ) & ( uparrow ) & ( uparrow ) & ( uparrow ) & ( uparrow ) \ hline end{tabular} |
11 |
| 1162 | The electrons are filled in various sub levels according to the order of their energies, is known as: A. Aufbau principle B. Pauli’s principle c. Hund’s rule D. ( n l^{x} ) principle |
11 |
| 1163 | What is the degeneracy of the level of ( boldsymbol{H} ) -atom that has energy ( left(-frac{R_{H}}{9}right) ? ) A . 16 B. 9 ( c cdot 4 ) ( D ) |
11 |
| 1164 | Assertion Isotopes of a particular element have nearly identical chemical behaviour. Reason They have identical electron configuration. A. Both assertion and reason are correct and reason is the correct explanation for assertion B. Both assertion and reason are correct but reason is not the correct explanation for assertion c. Assertion is correct but reason is incorrect D. Both assertion and reason are incorrect |
11 |
| 1165 | In nodal plane probability of finding an electron is: A . zero B. one c. maximum D. none of the these |
11 |
| 1166 | Assertion The nucleus of gold is stable even though there is a very strong coulombic repulsion among the protons. Reason The inverse square coulomb force is exactly balanced by another inverse square force which is very powerful than nuclear force. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 1167 | Assertion Threshold frequency is a characteristic for a metal. Reason Threshold frequency is a maximum frequency required for the ejection of electron from the metal surface. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
11 |
| 1168 | Q. 8 The period number in the long form of the periodic table is equal to (a) magnetic quantum number of any element of the period (b) atomic number of any element of the period o s (c) maximum principal quantum number of any element of the period 1993 (d) maximum azimuthal quantum number of any element of the period |
11 |
| 1169 | The number of sub-energy levels in any energy level is given by: ( A cdot n ) B. ( l ) ( c cdot m ) D. |
11 |
| 1170 | Assertion ( beta ) -particles are deflected less than ( alpha ) particles in electrical field. Reason ( beta ) -particles have very low mass. A. ( A ) is correct but ( R ) is wrong B. ( A ) is wrong but ( R ) is correct c. Both ( A ) and ( R ) are correct and ( R ) is correct explanation of ( A ) D. Both ( A ) and ( R ) are correct but ( R ) is not correct explanation of ( A ) |
11 |
| 1171 | Rutherford’s atomic model does not obey: A. faraday’s law of electrodynamics B. maxwell theory of electrodynamics c. newton’s law D. none of these |
11 |
| 1172 | Among the following groups which represents the collection of isoelectronic species? A ( cdot N O^{+}, C_{2}^{2-}, O_{2}^{-}, C O ) в. ( N_{2}, C_{2}^{2-}, C O_{2}^{-}, N O ) c. ( C O, N O^{+}, C N^{-}, C_{2}^{2} ) D. ( N O, C N^{-}, N_{2}, O_{2}^{-} ) |
11 |
| 1173 | The number of protons in an ion from which ( (Z-1) ) electrons are removed having its ionization energy ( 11800 k J ) ( m o l^{-1} ) is : A. three B. five c. four D. insufficient information |
11 |
| 1174 | Assertion ( 35 C l ) and ( _{17}^{37} C l ) have the same chemical ( 17^{7} ) properties. Reason Isotopes have the same number of protons and electrons and the same chemical reactions. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion. B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 1175 | Thomson’s model could not explain the : A. stability of an atom B. position of nucleus in an atom c. scattering of alpha particles D. all of above |
11 |
| 1176 | What will the ratio of the wavelength of the first line to that of the second line of Paschen series of H atom? A .256: 175 B. 175: 256 c. 15: 16 D. 24: 27 |
11 |
| 1177 | For Balmer series in the spectrum of hydrogen, the wave number of each line is given by ( overline{boldsymbol{v}}=boldsymbol{R}_{boldsymbol{H}}left[frac{mathbf{1}}{boldsymbol{n}_{mathbf{1}}^{2}}-frac{mathbf{1}}{boldsymbol{n}_{2}^{2}}right] ) where ( boldsymbol{R}_{boldsymbol{H}} ) is constant and ( n_{1}, n_{2} ) are integers, which of the following statements is (are) correct? 1. As wavelength decreases, the lines in the series converge. 2. The integer ( n_{1} ) is equal to 2 3. The ionization energy of hydrogen can be calculated from the wave number of these lines. 4. The lines of longest wavelength corresponds to ( n_{2}=3 ) ( A cdot 1,2 ) and 3 B. 2, 3 and 4 ( mathbf{c} cdot 1,2 ) and 4 D. 2 and 4 E. 2 only |
11 |
| 1178 | The maximum number of dectrons in ( Z n ) is : A . 10 B. 0 ( c cdot 2 ) D. 6 |
11 |
| 1179 | (A) Energy emitted in the transition ( (5 rightarrow 2) ) is less than that of ( . ) the transition ( (2 rightarrow 1) ) in all hydrogen like atoms. (R) The energy difference between 1st and 2 nd shell is greater than that of any two energy levels provided level (1) is not part of those two energy levels. A. Both (R) and (A) are true and reason is the. correct explanation of assertion B. Both (R) and (A) are true but reason is not correct explanation of assertion c. Assertion (A) is true but reason (R) is false D. Assertion (A) and reason (R) both are false E. Assertion (A) is false but reason (R) is true |
11 |
| 1180 | Argon has three isotopes with relative atomic masses of 36,38 and ( 40 . ) Given that the average relative atomic mass of naturally occurring argon is 39.95 Which of the following statements must be correct? A. 40 Ar is less abundant than ( ^{38} ) Ar B. ( 40 mathrm{Ar} ) is more abundant than either ( ^{36} mathrm{Ar} ) or ( ^{38} mathrm{Ar} ) C. ( 40 mathrm{Ar},^{38} mathrm{Ar} ) and ( ^{36} mathrm{Ar} ) are equally abundant D. ( 36 A r ) is more abundant than ( ^{40} A r ) |
11 |
| 1181 | The total energy of the electron in any orbit of one electron containing species is given by the expression: A ( cdot-e^{2} / r^{2} ) B . ( -n^{2} h^{2} / 2 pi^{2} Z^{2} e^{4} m ) c. ( -2 pi^{2} m Z^{2} e^{4} / n^{2} h^{2} ) D. ( n h / 2 pi ) |
11 |
| 1182 | Describe Bohrs model of the atom | 11 |
| 1183 | On the basis of composition, which of the following is a type of matter? A. Compound B. Solid c. Liquid D. Both b and c |
11 |
| 1184 | In which of the following autfnau principle is violated? ( A ) ( frac{uparrow}{2 s} ) begin{tabular}{c|c|c} hline( uparrow downarrow ) & ( uparrow ) & ( uparrow ) \ hline ( mathbf{2 p} ) & & \ hline end{tabular} B. ( frac{sqrt{1} downarrow}{2 s} ) ( c ) ( uparrow downarrow ) begin{tabular}{c|c|c|} hline( uparrow ) & ( uparrow ) & ( uparrow ) \ hline ( 2 p ) & & \ hline end{tabular} ( 2 mathrm{s} ) ( D ) ( frac{sqrt{1} mid}{2 s} ) begin{tabular}{c|c|c|c|c|} hline( uparrow downarrow ) & ( uparrow ) & ( uparrow ) \ hline ( 2 p ) & & & \ hline end{tabular} |
11 |
| 1185 | 73. The minimum kinetic energy required for ionization of a hydrogen atom is E, in case electron is collided with hydrogen atom. It is E, if the hydrogen ion is collided and E, when helium ion is collided. Then, (a) E, = E2 = E (b) E, > E> E (c) E; E, > E2 |
11 |
| 1186 | 19.7 kg of gold was recovered from a smuggler. The atoms of gold recovered are: A. 100 B. ( 6.02 times 10^{23} ) c. ( 6.02 times 10^{24} ) D. ( 6.02 times 10^{25} ) |
11 |
| 1187 | Q. 16 If travelling at same speeds, which of the following matter waves have the shortest wavelength? (a) Electron (b) Alpha particle (He2+) (c) Neutron (d) Proton |
11 |
| 1188 | Which of the following sets of quantum numbers is correct for an electron in ( 4 f ) orbital? ( A cdot n=4,1=3, m=+4, s=+frac{1}{2} ) B. ( n=4,1=4, m=-4, s=+frac{1}{2} ) ( c cdot n=4,1=3, m=+1, s=+frac{1}{2} ) D. ( n=4,1=2, m=2, s=+frac{1}{2} ) |
11 |
| 1189 | The mass number of ( X ) is 23 which contains 15 electrons. What is the atomic mass of ( boldsymbol{X} ) ? A . 38 amu B. 23 amu c. 18 amu D. None of above |
11 |
| 1190 | Assertion The mass number of hydrogen is equal to its atomic number. Reason H-atom has no neutrons. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion. B. Both Assertion and Reason are correct, but Reason is not the correct explanation for Assertion. C. Assertion is correct, but Reason is incorrect. D. Assertion is incorrect, but Reason is correct. |
11 |
| 1191 | A radioactive element decays by ( beta ) emission. If the mass of parent and daughter nuclide are ( m_{1} ) and ( m_{2} ) respectively, the energy liberated during the emission is : A. ( left[m_{1}-m_{2}-2 m_{e}right] c^{2} ) в. ( left[m_{1}-m_{4}-2 m_{e}right] c^{1} ) c. ( left[m_{1}-m_{1}-3 m_{e}right] c^{3} ) D. None of these |
11 |
| 1192 | According to the Bohr Theory, which of the following transitions in the hydrogen atom will give rise to the least energetic photon? A ( n=5 ) to ( n=3 ) 3 в. ( n=6 ) to ( n=1 ) c. ( n=5 ) to ( n=4 ) D. ( n=6 ) to ( n=5 ) |
11 |
| 1193 | From the following find out groups of isotopes, isobars and isotones: ( _{8}^{16} boldsymbol{O}_{, 19}^{39} boldsymbol{K}_{, 6}^{14} boldsymbol{C}_{, 92}^{239} boldsymbol{U}_{, 7}^{14} boldsymbol{N}_{, 20}^{40} boldsymbol{C} boldsymbol{a}_{, 92}^{238} boldsymbol{U}_{, 32}^{77} boldsymbol{G} ) |
11 |
| 1194 | Which of the following statement is false regarding isotopes? A. They are atoms of same element having same number of protons and electrons but different number of neutrons. B. Isotopes of an element have similar chemical perperties but different physical properties. C. All the isotopes of an element have same number of valence electrons D. The three isotopes of hydrogen (Protium, Deuterium and Tritium) contains one, two and three neutrons respectively. |
11 |
| 1195 | Consider Bohr theory for hydrogen atom. The magnitude of angular momentum, orbit radius and velocity of the electron in ( n^{t h} ) energy state in a hydrogen atom are ( l, r ) and ( v ) respectively. Find out the value of ( x ) if product of ( v, r ) and ( l ) is directly proportional to ( n^{x} ) |
11 |
| 1196 | 12. In a hydrogen-like atom an electron makes transition from an energy level with quantum number n to another with quantum number (n-1). If n >> 1. the frequency of radiation emitted is proportional to (a) (b)- (JEE Main 2015) |
11 |
| 1197 | In order for an electron to move from the second energy level (n=2) to the fourth energy level ( (n=4) ) the atom needs to: A. release heat B. release a photon C. maintain a constant energy D. release energy. E. absorb energy. |
11 |
| 1198 | What determines the size of isoelectronic species? A. Valence B. Nuclear charge c. lonization potential D. None of these |
11 |
| 1199 | Isotopes are those atoms which have same : A. atomic number B. atomic mass C. atomic charge D. all |
11 |
| 1200 | If the speed of electrons in Bohr’s first obtain of hydrogen is ( ^{prime} X^{prime} ) the speed of electrons in third orbit is: ( A cdot frac{X}{9} ) в. ( frac{x}{3} ) ( c .3 x ) D. 9.8 |
11 |
| 1201 | Assertion Nuclide ( _{13}^{30} A l ) is less stable than ( _{20}^{40} C a ) Reason Nuclide having odd number of protons and neutrons are generally unstable. |
11 |
| 1202 | Olle, 11, TWO, U TU. Q28. 2 (i) An atomic orbital has n = 3. What are the possible values of I and m,? (ii) List the quantum numbers (m, and I) of electron for 3d orbital. (iii) Which of the following orbitals are possible? 1p, 2s, 2p and 3f. |
11 |
| 1203 | 4. The de Broglie wavelength associated with a ball of mass 1 kg having kinetic energy 0.5 J is: (a) 6.626 x 10-34 m (b) 13.20 x 10-34 m (c) 10.38 x 10-21 m (d) 6.626 10-34 Å |
11 |
| 1204 | ( begin{array}{ll}text { List – I } & text { List – II } \ text { I) } Psi^{2} text { depends only upon distance } & begin{array}{l}text { a) } p- \ text { orbitals }end{array} \ begin{array}{l}text { 11) } Psi^{2} text { depends upon distance and on } \ text { one direction }end{array} & begin{array}{l}text { b) } mathrm{d}- \ text { orbital }end{array} \ begin{array}{l}text { III) } Psi^{2} text { depends upon distance and on } \ text { two directions }end{array} & begin{array}{l}text { c) } mathrm{f} text { – } \ text { orbital }end{array} \ begin{array}{l}text { IV) } Psi^{2} text { depends upon distance and on } \ text { three directions }end{array} & begin{array}{l}text { d) } mathrm{s} text { – } \ text { orbitals }end{array}end{array} ) ( A cdot|-d,| I-c,|I|-b, mid V-a ) B. ( |-c,||-b,|||-a, mid V-d ) C. ( |-d,| I-a,|I|-b, mid V-c ) D. I-d, II-a, III-c, IV-b |
11 |
| 1205 | Write the general outer electronic configuration of ( s-, p-, d- ) and ( f- ) block elements. |
11 |
| 1206 | 55. In X-ray tube, when the accelerating voltage Vis halved, the difference between the wavelength of K, line and minimum wavelength of continuous X-ray spectrum (a) remains constant (b) becomes more than two times (c) becomes half (d) becomes less than two times |
11 |
| 1207 | 56. X-rays emitted from a copper target and a molybdenum target are found to contain a line of wavelength 22.85 nm attributed to the K, line of an impurity element. The K. lines of copper (Z = 29) and molybdenum (Z = 42) have wavelengths 15.42 nm and 7.12 nm, respectively. The atomic number of the impurity element is (a) 22 (b) 23 (c) 24 (d) 25 |
11 |
| 1208 | (i) Calculate the number of electrons which will together weighs one gram. (ii) Calculate the mass and charge of one mole of electrons. |
11 |
| 1209 | A baseball of mass ( 200 mathrm{g} ) is moving with velocity ( 30 times 10^{2} mathrm{cm} / mathrm{s} ). If we can locate the baseball with an error equal in magnitude to the ( lambda ) of the light used ( mathbf{5 0 0 0} boldsymbol{A} ), then the uncertainty in momentum compared with the total momentum of base ball is: A ( .1 .75 times 10^{-29} ) В. ( 1.34 times 10^{-29} ) c. ( 1.89 times 10^{-29} ) D. ( 2.03 times 10^{-29} ) |
11 |
| 1210 | 03. Which orbital is non-directional ? Ans Sorbital |
11 |
| 1211 | Multiple Answer Question Bohr’s model could not explain the spectra: This question has multiple correct options A. of electron species having more than one electron B. in the presence of magnetic field c. of metal atoms D. in the presence of electric field |
11 |
| 1212 | Similar to electron diffraction, neutron diffraction microscope is also used for the determination of the structure of molecules. If the wavelength used here is ( 800 mathrm{pm} ), calculate the characteristic velocity associated with the neutron. |
11 |
| 1213 | Some hydrogen-like atom in ground state absorb ( n ) photons having the same energy and on de-excitation, it emits exactly ( n ) photons. Then the energy of absorbed photon may be: This question has multiple correct options A. ( 91.8 e V ) B. ( 40.8 e V ) c. ( 48.4 e V ) D. ( 54.4 e V ) |
11 |
| 1214 | For which of the following species sum spin quantum number of all electrons comes out to be zero? A ( cdot C r^{+}(Z=24) ) в. ( operatorname{Sc}(Z=21) ) c. ( C r^{+}(Z=29) ) D. ( N a(Z=11) ) |
11 |
| 1215 | Which among the following is incorrect of ( _{5} B ) in normal state? A. begin{tabular}{|c|c|c|c|c|} hline ( 2 s ) & ( 2 p ) & & \ hline( uparrow uparrow ) & & ( uparrow ) & \ hline end{tabular} B. begin{tabular}{|c|c|c|c|c|} hline ( 2 s ) & multicolumn{3}{|c|} {( 2 p )} \ hline( uparrow ) & ( uparrow ) & ( uparrow ) & multicolumn{2}{|c|} { Against aufbau principle as well as Hund’s rule } \ hline end{tabular} ( c ) begin{tabular}{c|c|c|c|} ( 2 s ) & multicolumn{2}{c} {( 2 p )} \ hline( uparrow uparrow ) & ( uparrow ) & & \ hline end{tabular} Violation of Pauli’s exclusion principle and not Hund’s rule D. ( 2 p ) ( 2 s ) ( uparrow downarrow ) ( : quad ) Against aufbau principle |
11 |
| 1216 | When an ( alpha ) -particle is emitted A. element moves 2 places to the right in the periodic table B. element moves one place to the left C. element moves 2 places to the left in the periodic table D. elements maintains its position |
11 |
| 1217 | Which transition corresponds to series limits for paschen series? |
11 |
| 1218 | One proton weighs more than: A . 1,800 electrons B. 1,800 neutrons c. Above both options are correct D. None of the above |
11 |
| 1219 | Q21. When is the energy of electron regarded as zero? | 11 |
| 1220 | The frequency of light emitted for the transition ( n=4 ) to ( n=2 ) of ( H e^{+} ) is equal to the transition in ( mathrm{H} ) atom corresponding to which of the following? A ( . n=3 ) to ( n=1 ) в. ( n=2 ) to ( n=1 ) c. ( n=3 ) to ( n=2 ) D. ( n=4 ) to ( n=3 ) |
11 |
| 1221 | An element with atomic number 117 is known as: A. nihonium B. flerovium c. tennessine D. roentgenium |
11 |
| 1222 | Rutherford’s alpha Scattering experiment showed that: A. the atoms were smashed up by alpha particles B. the atoms consisted or protons in a matrix of electrons C. the nucleus was quite large and was positively charged D. the nucleus was very small and positively charged |
11 |
| 1223 | Determine the number of electron in the isotope of ‘H’ (mass no. 2). ( mathbf{A} cdot mathbf{1} ) B. 2 ( c cdot 0 ) D. |
11 |
| 1224 | An ( alpha ) – particle of ( mathrm{KE} mathbf{5 . 4} M e V ) is projected towards ( C r ) – nucleus ( (Z= ) 24). What is its distance of closest approach? ( left(e=1.6 times 10^{-19} Cright) ) |
11 |
| 1225 | The potential energies of first, second and third Bohr’s orbits of ( H e^{+} ) cation are ( E_{1}, E_{2} ) and ( E_{3} . ) The correct sequence of these energies is: A ( . E_{1}>E_{2}>E_{3} ) B . ( E_{1}=E_{2}>E_{3} ) c. ( E_{1}=E_{2}=E_{3} ) D. ( E_{3}>E_{2}>E_{1} ) |
11 |
| 1226 | Value of all quantum number for 4 th electron of ( left(_{16} Sright) ) |
11 |
| 1227 | The number of times by which an electron is lighter than a hydrogen atom: A . 1840 в. 1837 ( c .1836 ) D. none of the above |
11 |
| 1228 | Name the compounds used in preparation of nylon-66. A. E-caprolactum B. Hexamethylenediamine and adipic acid C. Dimethyl tetraphthalate D. Hexamethylene diamine |
11 |
| 1229 | In a sample, electronjumps from ( 5^{t h} ) excited state to ground state then number of spectral lines in visible range will be: A . 4 B. 3 c. 2 ( D ) |
11 |
| 1230 | Among the following, the isoelectronic species is/ are: (i) ( boldsymbol{O}^{2-}, boldsymbol{F}^{-}, boldsymbol{N} boldsymbol{a}^{+}, boldsymbol{M} boldsymbol{g}^{2+} ) ( (text { ii }) N a^{+}, M g^{+}, A l^{3+}, F^{-} ) (iii) ( N^{3-}, O^{2-}, F^{-}, N e ) ( A cdot ) (i) and (ii) B. (i), (ii) and (iii) c. (ii) and (iii) D. (i) and (iii) |
11 |
| 1231 | Isotope per Natural abundance [ begin{array}{ll} ^{1} boldsymbol{H} & mathbf{9 9 . 9 8 5} \ ^{2} boldsymbol{H} & mathbf{0 . 0 1 5} end{array} ] The average atomic mass of hydrogen using the following data is |
11 |
| 1232 | Quantum theory was postulated by: A. Rutherford B. Maxwell c. Max Planck D. Becquerel |
11 |
| 1233 | What are isoelectronic spices? give example? | 11 |
| 1234 | A small particle of mass ( m ) moves in such a way that ( P . E=-frac{1}{2} m k r^{2}, ) where ( k ) is a constant and ( r ) is the distance of the particle from origin. Assuming Bohr’s model of quantization of angular momentum and circular orbit, ( r ) is directly proportional to: ( mathbf{A} cdot n^{2} ) в. c. ( sqrt{n} ) D. none of these |
11 |
| 1235 | Based on equation ( boldsymbol{E}=mathbf{2 . 1 7 8} times mathbf{1 0}^{mathbf{1 8}} mathbf{J} ) ( left(frac{Z^{2}}{n^{2}}right), ) certain conclusions are written Which of them is not correct? A. The negative sign in equation simply means that the energy of electron bound to the nucleus is lower than i would be if the electrons were at the infinite distance from the nucleus B. Larger the value of n, the larger is the orbit radius c. Equation can be used to calculate the change in energy when the electron changes orbit D. For ( n=1 ), the electron has a more negative energy that it does for ( n=6 ) which means that the electron is more loosely bound in the smallest allowed orbit |
11 |
| 1236 | The minimum possible angular momenturn of an election present in an orbital is ( ldots ldots . . . . . . ) if the magnetic quanthem number associated with this orbinal are -1,0,+1 A ( cdot frac{5 h}{2 pi} ) в. ( frac{3 h}{2 pi} ) ( c cdot frac{h}{2 pi} ) D. ( frac{h}{pi} ) |
11 |
| 1237 | ( ^{87} ) Rb undergoes ( beta ) -decay ( left(t_{1 / 2}=4.7 timesright. ) ( left.10^{10} text { year }right) ) to form ( ^{87} ) Sr. An analysis of the rock sample shows relative number of ( ^{87} mathrm{Sr} ) and ( ^{87} ) Rb atoms ( 0.052: 1 . ) If all the ( ^{87} mathrm{Sr} ) is formed from ( beta ) -decay of ( ^{87} mathrm{Rb} ) The age of the rock is : A . ( left[2.21 times 10^{9} text { year }right] ) B . ( left[3.43 times 10^{9} text { year }right] ) C . ( left[4.13 times 10^{9} text { year }right] ) D. none of these |
11 |
| 1238 | Velocity of de Broglie wave is given by: ( ^{A} cdot frac{c^{2}}{v} ) в. ( frac{h v}{m c} ) ( c cdot frac{m c^{2}}{h} ) D. ( v lambda ) |
11 |
| 1239 | An absorption of ( 12.088 e V ) energy by an electron in ground state of ( boldsymbol{H} ) -atom brings in the excitation of electron to which orbit? A. Two B. Three c. Four D. Not possible. Minimum ene ( 6 e^{v} ) |
11 |
| 1240 | State True or False. High pressure and low voltage should be maintained in the discharge tube for the production of cathode rays. A . True B. False |
11 |
| 1241 | Presence of electrons is shown by three dimensional shape of orbit with: A. high probability B. low probability c. no probability D. slow ratio |
11 |
| 1242 | Arrangement of the following group of orbitals in which they fill with electrons ( (5 f, 6 p, 4 p, 6 s, 4 d, 4 f) ) ( mathbf{A} cdot 4 p, 4 d, 6 s, 4 f, 6 p, 5 f ) B. ( 6 s, 4 d, 4 f, 5 f, 4 p, 6 p ) ( mathbf{c} .6 s, 4 p, 4 d, 4 f, 5 f, 6 p ) D. ( 4 d, 4 p, 4 f, 5 f, 6 s, 6 p ) |
11 |
| 1243 | Give the electronic configurations of the following: a. ( H^{-} ) b. ( mathrm{He}^{+} ) c.F ( ^{-} ) d. ( mathrm{N}^{2+} ) t |
11 |
| 1244 | Splitting of spectral lines in the presence of electric field is known as: A. Stark effect B. Zeeman’s effect c. compton effect D. Moseley’s effect |
11 |
| 1245 | Proton was discovered by: A. Thomson B. Rutherford c. chadwick D. Goldstein |
11 |
| 1246 | Most of the alpha particles go straight through the foil if it is passed through a thin metal foil. This is due to the reason that: A. alpha particles are much heavier than electrons B. alpha particles are positively charged c. most part of the atom is empty D. alpha particles move with the high velocity |
11 |
| 1247 | What are the limitations of Rutherford’s model of the atom? |
11 |
| 1248 | The velocity of an ( e^{-} ) in excited state of H-atom is ( 1.093 times 10^{6} ) m/s. What is the circumference of this orbit? A ( cdot 3.32 times 10^{-10} mathrm{m} ) В. ( 6.64 times 10^{-10} mathrm{m} ) c. ( 13.30 times 10^{-10} mathrm{m} ) D. ( 13.28 times 10^{-8} mathrm{m} ) |
11 |
| 1249 | The number of electrons, protons and neutrons in an atom whose atomic number is 11 and mass number 23 will be: A. 11,11,12 B. 11,12,11 c. 12,11,11 D. 23,11,23 |
11 |
| 1250 | Explain the reason for exceptional electroic congiguration of copper and chromium. | 11 |
| 1251 | ( 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{6} 4 s^{2} ) The given electronic configuration is for: A . Na B. Fe c. ( C l^{-} ) D. Rb E ( . C a^{+} ) |
11 |
| 1252 | The maximum of electrons in ( mathrm{H} ) atom that will emit maximum energy is : ( A cdot n_{3} rightarrow n_{1} ) в. ( n_{4} rightarrow n_{3} ) ( mathrm{c} cdot mathrm{n}_{5} rightarrow mathrm{n}_{4} ) ( mathrm{D} cdot mathrm{n}_{6} rightarrow mathrm{n}_{5} ) |
11 |
| 1253 | Calculate the wavelength and energy of radiation emitted for the electronic transition from infinity to stationary state of the hydrogen. B. 3.142 ( times 10^{18} ) 」 C . ( 1.021 times 10^{18} mathrm{J} ) D . 0.536 ( times 10^{18} ) 」 |
11 |
| 1254 | Statement 1: Two isotopes of the same element have the same mass number Statement 2: Isotopes have the same number of protons. A. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1 B. Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1. C. Statement 1 is correct but Statement 2 is not correct. D. Statement 1 is not correct but Statement 2 is correct. E. Both Statement 1 and Statement 2 are not correct. |
11 |
| 1255 | The e/m ratio for cathode rays: A. is constant B. varies as the atomic number of the element forming the cathode in the discharge tube changes C. varies as the atomic number of the gas in the discharge tube varies D. has the smallest value when the discharge tube is filled with hydrogen |
11 |
| 1256 | The wavelength of first line of Balmer spectrum of hydrogen will be: в. ( 4101 hat{A} ) ( c .6569 hat{A} ) D. ( 4861 A ) |
11 |
| 1257 | The energy of the first orbit of ( boldsymbol{H} boldsymbol{e}^{+} ) is ( -871.6 times 10^{-20} J . ) The energy of the electron in the first orbit of hydrogen would be: ( begin{array}{lll}text { A. }-871.6 times & 10^{-20} Jend{array} ) B . ( -435.8 times quad 10^{-20} J ) ( begin{array}{lll}text { C. }-217.9 times & 10^{-20} Jend{array} ) begin{tabular}{ll} D. ( -108.9 times ) & ( 10^{-20} mathrm{J} ) \ hline end{tabular} |
11 |
| 1258 | The subatomic particle which remains unchanged during the chemical reaction is/are
This question has multiple correct options |
11 |
| 1259 | When a certain metal is irradiated with a radiation of frequency ( 3.2 times 10^{16} S^{-1} ) the photo electrons emitted had twice the kinetic energy as did the phototelectrons emitted when the same metal was irradiated with radiation of frequency ( 2 times 10^{16} S^{-1} . ) Calculate threshold frequency of metal. |
11 |
| 1260 | A neutral atom of an element has ( 2 mathrm{K}, 8 mathrm{L} ) ( 9 mathrm{M} ) and ( 2 mathrm{N} ) electrons. The total number of ( s ) electrons are: ( A cdot 8 ) B. 6 ( c cdot 4 ) D. 10 |
11 |
| 1261 | Could aluminium foil serve the purpose in ( alpha ) – ray scattering experiment. Explain the reason behind it. |
11 |
| 1262 | Calculate the de Broglie wavelength for a beam of electron whose energy is ( mathbf{1 0 0} e V: ) ( mathbf{A} cdot 1 A^{0} ) B . ( 1.23 A^{circ} ) c. ( 2.46 A^{circ} ) D. None of these |
11 |
| 1263 | No.of nodal planes in ( 3 d ) -orbitals are : ( A cdot 2 ) B. 4 ( c cdot 5 ) D. 10 |
11 |
| 1264 | The atomic number of an element is determined by: A. the number of electrons in one atom B. the number of neutrons in one atom c. the valency of the element D. the number of protons in one atom |
11 |
| 1265 | Which of the following was not explained by Bohr’s atomic model A. Splitting of spectral lines in Magnetic field B. Splitting of spectral lines in electric field C. Bohr model could not explain the uncertainty principle of Heisenberg. D. All of the above |
11 |
| 1266 | According to J.J. Thomson’s atomic model, negative charges are embedded in : A. a lump of positive charge B. lump of neutral charge c. a lump of small atoms D. nucleus |
11 |
| 1267 | Isotopes are: A. atoms of same element, having the different atomic number but same mass numbers B. atoms of same element, having the same atomic number but different mass numbers C. atoms of different elements with different atomic numbers, which have the same mass number D. atoms of different elements with same atomic numbers, which have different mass numbers |
11 |
| 1268 | An electron in ( H ) -atom in ground state absorbs 1.5 times as much energy as the minimum required for its escape (i.e., ( 13.6 e V) ) from the atom. Calculate the wavelength of emitted electron. A . ( lambda=4.70 times 10^{-10} mathrm{m} ) В. ( lambda=61 times 10^{-9} m ) c. ( lambda=4.70 times 10^{-14} mathrm{m} ) D. ( lambda=2.7 times 10^{-10} mathrm{m} ) |
11 |
| 1269 | In one average life: A. half the radioactive nuclei decay B. less than half the radioactive nuclei decay C. more than half the radioactive nuclei decay D. all the nuclei decay |
11 |
| 1270 | Which is correct for any kind of species? ( mathbf{A} cdotleft(E_{2}-E_{1}right)>left(E_{3}-E_{2}right)>left(E_{4}-E_{3}right) ) B ( cdotleft(E_{2}-E_{1}right)<left(E_{3}-E_{2}right)<left(E_{4}-E_{3}right) ) ( mathbf{C} cdotleft(E_{2}-E_{1}right)=left(E_{3}-E_{2}right)=left(E_{4}-E_{3}right) ) D ( cdotleft(E_{2}-E_{1}right)=1 / 4left(E_{3}-E_{2}right)=1 / 9left(E_{4}-E_{3}right) ) |
11 |
| 1271 | Which of the following properties are similar for isotopes? A. Physical properties B. Chemical properties c. Both physical and chemical properties D. Neither physical nor chemical properties |
11 |
| 1272 | 31. Magnetic field at the center (at nucleus) of the hydrogen- like atoms (atomic number = z) due to the motion of electron in nth orbit is proportional to (b) n* |
11 |
| 1273 | Given set of quantum numbers for a multi-electron atom is: ( boldsymbol{n} ) ( l ) ( m ) ( s ) 2 ( begin{array}{cc}0 & 0end{array} ) ( +1 / 2 ) 2 ( -1 / 2 ) What is the next higher allowed set of ‘ ( n ) and ‘l’ quantum numbers for this atom in the ground state? A. ( n=2, l=0 ) В. ( n=2, l=1 ) c. ( n=3, l=0 ) D. ( n=3, l=1 ) |
11 |
| 1274 | A photon of wavelength ( 4 times 10^{-7} mathrm{m} ) strikes on the metal surface, the work function of the metal is 2.13 eV. Calculate the energy of the photon (eV) |
11 |
| 1275 | Which of the following orbit is impossible for an electron according to Bohr’s theory? A ( cdot m v r=frac{h}{2 pi} ) B. ( m v r=frac{3 h}{4 pi} ) c. ( _{m v r}=frac{2 h}{pi} ) D. ( m v r=frac{4 h}{2 pi} ) |
11 |
| 1276 | What transition of ( L i^{+2} ) spectrum will have same wavelength as that of second line of Balmer series in ( boldsymbol{H} boldsymbol{e}^{+} ) spectrum? |
11 |
| 1277 | Assertion In an atom, the velocity of electron in the higher orbits keeps on decreasing. Reason Velocity of electrons is inversely proportional to the radius of the orbit. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion, B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 1278 | The atomic numbers of two elements A and B are 11 and 12 respectively. Which element exhibits highest metallic property ? Write the molecular formula of the compounds formed when theses elements combine with the element ‘Z’ having atomic number 8 |
11 |
| 1279 | Which of the following statements are correct? This question has multiple correct options A ( cdot ) The angular momentum of ( 3 p ) -orbital is ( frac{h}{sqrt{2} pi} ) B. The sixth electron of carbon atom has the quantum numbers ( n=2, ell=1, m=0, s=+frac{1}{2} ) or ( -frac{1}{2} ) C. Magnetic moment of ( V^{4+} ) ions is 1.73 BM ( (mathrm{V}=23) ) D. For azimuthal quantum number ( ell=3 ), the maximum number of electrons is 6 |
11 |
| 1280 | Mass number is silghtly less than the actual atomic mass. Give reasons. | 11 |
| 1281 | The total energy emitted when electrons of ( 1.0 mathrm{g} ) atom of hydrogen undergo transition giving the spectral line of lowest energy in the visible region of its atomic spectrum is: ( left[text { Given }: boldsymbol{E}_{mathbf{1}(boldsymbol{H})}=mathbf{2 . 1 7 6} times mathbf{1 0}^{-mathbf{1 8}}right] ) A . ( 1.82 times 10^{5} mathrm{J} / mathrm{mol} ) В. ( 1.96 times 10^{5} mathrm{J} / mathrm{mol} ) c. ( 2.01 times 10^{5} mathrm{J} / mathrm{mol} ) D. ( 2.06 times 10^{5} mathrm{J} / mathrm{mol} ) |
11 |
| 1282 | I: Gas-phase elements absorb or emit only specific wavelengths of visible light when excited by an electric current. Il: The energy levels that electrons can occupy in gas-phase atoms and molecules are continuous. |
11 |
| 1283 | The ( E_{1} ) of ( H ) is ( 13.6 e V . ) It is exposed to electromagnetic waves of ( 1028 dot{A} ) and gives out induced radiation. Find the wavelengths of these induced radiation. This question has multiple correct options |
11 |
| 1284 | The electron density of ( 3 d_{x y} ) orbital in ( Y Z ) plane is: A . 50% B. 95% c. 33.33% D. 0% |
11 |
| 1285 | Q1. (i) Calculate the number of electrons which will together weigh one gram. (ii) Calculate the mass and charge of one mole of electrons. |
11 |
| 1286 | The last member of ( 4 n+1 ) series is an isotope of lead. A. True B. False |
11 |
| 1287 | Assertion During ( beta ) -decay, a new element with atomic number greater than one is obtained. Reason Protons and neutrons keep on changing into one another through meson A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 1288 | The element used by Rutherford in his famous scattering experiment was A. Gold B. Tin c. Silver D. Leadd |
11 |
| 1289 | The electronic configuration ( 1 s^{2} 2 s^{2} 2 p x^{1} 2 p y^{1} 2 p z^{1} ) is of: A. B. c. Na D. |
11 |
| 1290 | The graph between ( |Psi|^{2} ) and ( r( ) radial distance) is shown below. This represents: A . 3s orbital B. 1s orbital c. 2p orbital D. 2s orbital |
11 |
| 1291 | Arrange the following in increasing energy levels: ( A cdot 5 p<4 d<3 p<4 f<5 d<6 s ) ( B .3 p<4 d<5 p<6 s<4 ) ( c cdot 3 p<4 d<5 p<4 f<6 s ) D. ( 3 p<4 d<5 p<4 f<6 p ) |
11 |
| 1292 | How many unbonded pairs of electrons are found in a neutral atom of sulfur? A. Three B. Two c. one D. None |
11 |
| 1293 | In Bohr series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of the following inter – orbit jumps of the electron for Bohr orbits in an atom of hydrogen ? ( mathbf{A} cdot 3 rightarrow 1 ) B . ( 5 rightarrow 2 ) c. ( 2 rightarrow 5 ) D. ( 3 rightarrow 2 ) |
11 |
| 1294 | Compared to the mass of lightest nucleus the mass of an electron is only: A ( cdot frac{1}{80} ) B . ( frac{1}{360} ) ( c cdot frac{1}{1800} ) D. ( frac{1}{1000} ) |
11 |
| 1295 | The energy required to melt 1 g ice is ( 33 J . ) The number of quanta of radiation of frequency ( 4.67 times 10^{13} ) sec ( ^{-1} ) that must be absorbed to melt ( 10 mathrm{g} ) ice is: A ( cdot 1.065 times 10^{22} ) B. ( 3.205 times 10^{23} ) c. ( 9.076 times 10^{20} ) D. none of the above |
11 |
| 1296 | Atomic number of calcium is ? ( A cdot 18 ) B. 19 c. 20 D. 21 |
11 |
| 1297 | Na AL 13. From the figure describing photoelectric effect, we may infer correctly that (a) Na and Al both have the same threshold frequency (b) Maximum kinetic energy for both the Ro Re metals depend linearly 10 on the frequency. Frequency (c) The stopping potentials are different for Na and Al for the same change in frequency (d) Al is a better photosensitive material than Na. Stopping potential |
11 |
| 1298 | The element with electronic configuration 2,8,6 is A. metallic B. non-metallic c. metalloid D. None of these |
11 |
| 1299 | One molecule of a substance absorbs one quantum of energy. The energy involved when 1.5 moles of the substance absorb red light of frequency ( 7.5 times 10^{14} s e c^{-1} ) will be? A ( cdot 4.49 times 10^{5} J ) B . ( 2.24 times 10^{5} J ) c. ( 9.23 times 10^{7} J ) D. ( 2.24 times 10^{7} J ) |
11 |
| 1300 | A radioactive atom ‘ ( X^{prime} ) emits a ( beta- ) particle to produce an atom ‘ ( Y ) ‘ which then emits an ( alpha ) -particle to given an ( operatorname{atom}^{prime} Z^{prime}: ) (1) The atomic number of ‘ ( X^{prime} ) is less than that of ( ^{prime} Z^{prime} ) (2) The atomic number of ‘ ( Y ) ‘ is less than that of ( ^{prime} Z^{prime} ) (3) The mass number of ‘ ( X^{prime} ) is same as that of ‘ ( Y ) A. 1,2 and 3 are correct B. 1 and 2 are correct c. 2 and 3 are correct D. 3 is correct |
11 |
| 1301 | The lightest radioactive isotope in periodic table is: A. tritium B. deuterium c. protium D. none of these |
11 |
| 1302 | 2.18 Out of the following pairs of electrons, identify the pairs of electro present in degenerate orbitals. (a) (i) n = 3, 1=2 , m = -2 ,m, =-= (ii) n = 3,1=2 m = -1, m, (b) (i)n=3,1=1, m, =1, m = + (ii) n = 3, 1=2, m, =1, m, = + II + (c) (i)n=4,1 =1, m, =1, m, = + (ii) n=3,1=2, m, =1, m= + + (d) (i) n=3,1=2, m, = +2,m=- (ii) n=3, 1=2,m, = +2,m, + |
11 |
| 1303 | The number of nodal planes in a ( boldsymbol{P}_{boldsymbol{x}} ) orbital is: A. one B. Two c. Three D. zero |
11 |
| 1304 | Calculate the frequency of the radiation emitted when an electronjumps from ( n=3 ) to ( n=2 ) in a hydrogen atom is: A ( cdot 4.57 times 10^{14} s^{-1} ) В. ( 4.57 times 10^{16} s^{-1} ) ( c cdot 5.01 times 10^{14} s^{-1} ) -1 D. ( 5.01 times 10^{16} s^{-1} ) |
11 |
| 1305 | Electrons with a kinetic energy of ( 6.023 times 10^{4} J / ) mol are evolved from the surface of a metal when it is exposed to radiation of a wavelength of 600 nm. The minimum amount of energy required to remove an electron from the metal atom is: A ( .2 .3125 times 10^{-19} mathrm{J} ) B . ( 3 times 10^{-19} J ) ( c cdot 6.02 times 10^{-19} J ) ( J ) D. ( 6.62 times 10^{-34} J ) |
11 |
| 1306 | The number of electrons in a neutral atom is equal to its: A. atomic mass number B. neutron c. valency D. proton |
11 |
| 1307 | The ion that has different number of electrons in the ultimate and penultimate shells is : A . ( N a^{text {t }} ) в. ( K^{+} ) c. ( C l^{-} ) D. ( C a^{2} ) |
11 |
| 1308 | Calculate the ratio of radii of first, second and third orbits of a hydrogen atom |
11 |
| 1309 | A gas absorbs a photon of ( 355 n m ) and emits two wavelengths. If one of the emission is at ( 680 n m ), the other is at: ( mathbf{A} .518 n m ) в. ( 1035 n m ) c. ( 325 n m ) D. ( 743 n m ) |
11 |
| 1310 | The energy change in an electron jump is given by: A. ( Delta E=h c / lambda ) B. ( Delta E=h lambda / c ) c. change in kinetic energy D. azimuthal quantum number |
11 |
| 1311 | Multiple Answer Question In Rutherford’s model of atom: This question has multiple correct options A. atom is a planetary model B. electrons never loose nor gain energy C. electron revolve around nucleus with high velocities to counter balance the forces of electrostatic forces of attraction between protons and electrons D. electrons do not move at all |
11 |
| 1312 | The wavelength of radiation emitted, when in ( H e^{+} ) electron falls from infinity to ground state would be: ( left(R=1.097 times 10^{7} m^{-1}right) ) A ( .2 .2 times 10^{-8} m ) th B. 2.2 ( times 10^{-9} mathrm{m} ) c. ( 120 m ) D. ( 22 times 10^{7} mathrm{m} ) |
11 |
| 1313 | Calculate the wave number of the fourth line of Balmer series. |
11 |
| 1314 | Electronic configuration of chlorine is : A ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{1} 3 p^{6} ) B . ( 1 s^{2} 2 s^{2} 2 p^{5} 3 s^{2} 3 p^{6} ) c. ( 1 s^{2} 2 s^{2} 2 p^{6} 4 s^{2} 4 p^{5} ) D. ( 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{5} ) |
11 |
| 1315 | The number of unpaired electrons in chromium atom are: A .2 B. 3 ( c cdot 4 ) ( D ) |
11 |
| 1316 | The wave number of the radiation whose quantum 1 erg is: A. ( 5 times 10^{15} mathrm{cm}^{-1} ) B. ( 15 times 10^{5} mathrm{cm}^{-1} ) c. ( 1.5 times 10^{15} mathrm{cm}^{-1} ) D. ( 5 times 10^{5} mathrm{cm}^{-1} ) |
11 |
| 1317 | In hydrogen spectrum, the spectral line of Balmer series having lowest wavelength is: A. ( H_{alpha}- ) line B. ( H_{beta}- )line ( mathbf{c} cdot H_{gamma}-operatorname{line} ) D. ( H_{delta}- ) line |
11 |
| 1318 | Which of the following statements is correct? A. The maximum number of unpaired electrons in a subshell is equal to ( 2 l+1 ) B. The maximum value of magnetic moment for an atom with ( l=2 ) subshell is 3.9 C. The total spin of ( 3 d^{6} ) configuration is 3. D. Both A and B |
11 |
| 1319 | What will be the number of waves formed by a Bohr electron in one complete revolution in its second orbit? A. Three B. Two c. one D. zero |
11 |
| 1320 | The angular part of the wave function depends on the quantum numbers are: This question has multiple correct options ( A cdot n ) B. ( l ) ( c . m ) D. |
11 |
| 1321 | The commonly used pain reliever, aspirin, has the molecular formula ( C_{9} H_{8} O_{4} . ) If a sample of aspirin contains ( 0.968 g ) of carbon, what is the mass of hydrogen in the sample? A ( .0 .717 g ) в. ( 0.0717 g ) c. ( 8.000 g ) D. ( 0.645 g ) |
11 |
| 1322 | A hydrogen atom initially in the ground level absorbs a photon, which excites it to the ( n=4 t h ) level. Determine the wavelength and frequency of photon. |
11 |
| 1323 | Q42. An element with mass number 81 contains 31.7% more neutrons as compared to protons. Assign the symbol to the element. |
11 |
| 1324 | is defined as the number of protons present in the nucleus of an atom. A. Atomic number B. Mass number c. Both a and D. None of these |
11 |
| 1325 | For an atom of a given element, the number of electrons is given by A. the number of protons ( + ) number of neutrons B. the atomic number of the element c. the number of proton – number of neutrons D. the mass number of the element |
11 |
| 1326 | State True or False: The electron density in ( x y ) -plane of ( 3 d_{x^{2}-y^{2}} ) orbital is zero. A. True B. False |
11 |
| 1327 | Assertion All the isotopes of a given element show same chemical behaviour. Reason Isotopes have different number of neutrons present in the nucleus. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 1328 | Bohr’s theory is not applicable for: A . ( H ) B . ( L i^{2} ) ( mathrm{c} cdot H^{+} ) D. ( B e^{3} ) |
11 |
| 1329 | For the Paschen series the value of ( n_{1} ) and ( n_{2} ) in the expression ( Delta E=R_{H} times ) ( cleft[frac{1}{n_{1}^{2}}-frac{1}{n_{2}^{2}}right] ) is: A ( cdot n_{1}=1, n_{2}=2,3,4 ) в. ( n_{1}=2, n_{2}=3,4,5 dots ) c. ( n_{1}=3, n_{2}=4,5,6 ) D. ( n_{1}=4, n_{2}=5,6,7 ) |
11 |
| 1330 | Which of the following would not be attracted or deflected while traveling through an electric field? I. Gamma ray II. Beta particle III. neutron. A . i only B. ii only c. i and ii only D. i and iii only |
11 |
| 1331 | The excited state(n) of the atom is : | 11 |
| 1332 | The de-Broglie wavelength of a ( H e- ) atom in a container at ( 300 K ) is: ( left(operatorname{luse} v_{a v g}right) ) ( mathbf{A} cdot 0.79 stackrel{circ}{A} ) B ( cdot 0.45 stackrel{circ}{h} ) ( c cdot 0.68 stackrel{circ}{8 A} ) D. ( 0.89 stackrel{circ}{A} ) |
11 |
| 1333 | Which shape is associated with the orbital designated by ( n=2, l=1 ? ) A. Spherical B. Tetrahedral c. Dumb-bell D. Pyramidal |
11 |
| 1334 | The electronic configuration of an element is ( 1 s^{2}, 2 s^{2} 2 p^{6}, 3 s^{2} 3 p^{6} 3 d^{5}, 4 s^{1} ) This represents its: A. excited state B. ground state c. cationic form D. anionic form |
11 |
| 1335 | Matter has both A. mass, volume B. mass, weight C. life, particle D. None of the above |
11 |
| 1336 | In the hydrogen atom, the kinetic energy of the electron is ( 3.4 e V . ) The distance of that electron from the nucleus: A . ( 2.116 AA ) в. ( 0.529 AA ) c. ( 1.587 hat{h} ) D. ( 21.16 AA ) |
11 |
| 1337 | Give the name and symbol for each of the atoms which have the ground state electronic configuration in their outer shells: ( (a) 2 s^{2}(b) 3 s^{2} 3 p^{5}(c) 3 s^{2} 3 p^{6} 4 s^{2}(d) 3 s^{2} 3 p^{6} ) |
11 |
| 1338 | Q11. What is common between d and d 2,2 orbitals? AD11:11 XY |
11 |
| 1339 | For which of the following orbital wave function does not change its sign at any distance from the nucleus? A. 3d B. 2p ( c cdot 2 s ) ( D cdot 1 ) s |
11 |
| 1340 | How does the Bohr theory of the hydrogen atom differ from that of Schrodinger? |
11 |
| 1341 | The change in orbital angular momentum corresponding to an electron transition inside a hydrogen atom can be: A ( frac{h}{4 pi} ) в. ( frac{h}{p i} ) ( c cdot frac{h}{2 pi} ) D. ( frac{h}{8 pi} ) |
11 |
| 1342 | Why can no two elements have a same atomic number? |
11 |
| 1343 | If series limit (in ( n m ) ) of a series of hydrogen spectrum which contains a photon of wavelength 1278.35 nm is expressed as ( frac{1240}{x}, ) then ( x ) is: (Given ( : h c=1240 mathrm{eV}-mathrm{nm}) ) A . ( 1.51 e V ) в. ( 2 e V ) c. ( 3.4 e V ) D. ( 0.66 e V ) |
11 |
| 1344 | Write down the four quantum number for ( 8 t h ) electron of oxygen atom? A ( cdot n=2, l=1, m=+2 ) or ( -2, s=+frac{1}{2} ) or ( -frac{1}{2} ) B. ( n=2, l=1, m=+1 ) or ( -1, s=+frac{1}{2} ) or ( -frac{1}{2} ) c. ( n=2, l=1, m=0, s=+frac{1}{2} ) or ( -frac{1}{2} ) D. ( n=2, l=0, m=0, s=+frac{1}{2} ) or ( -frac{1}{2} ) |
11 |
| 1345 | Which of the following orbitals are in the increasing order of energy. ( mathbf{A} cdot 1 s, 2 s, 2 p, 3 s ) В. ( 4 s, 3 s, 3 p, 4 d ) c. ( 5 p, 4 d, 5 d, 4 f, 6 s ) D. ( 4 p, 2 s, 3 s, 2 p ) |
11 |
| 1346 | If the following matter waves travel with equal velocity, the longest wavelength is that of a/an: A . electron B. proton c. neutron D. particle |
11 |
| 1347 | Which of the following choices shows the ground state electron configuration of an ion of a halogen? ( mathbf{A} cdot 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{5} ) B . ( 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} ) C ( cdot 1 s^{2} 2 s^{2} 2 p^{6} 2 d^{10} 3 s^{2} 3 p^{5} ) D. ( 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{1} ) |
11 |
| 1348 | Assertion Number of waves in an orbit of atom is equal to number of that orbit, Reason Number of waves in an orbit is derived by ( frac{2 pi r_{n}}{lambda} ) Read the above assertion and reason and choose the correct option regarding ¡t A. Statement is correct but Explanation is wrong. B. Statement is wrong but Explanation is correct. c. Both Statement and Explanation are correct and Explanation is the correct explanation for Statement D. Both Statement and Explanation are correct but Explanation is not the correct explanation for Statement |
11 |
| 1349 | Which is the correct graph? ( A ) B. ( c ) ( D ) |
11 |
| 1350 | Which of the following contains up to 10 electrons. A . ( 1 s ) B . ( 2 s ) ( c cdot 3 s ) D. ( 3 p ) E . ( 3 d ) |
11 |
| 1351 | Thomson”s atomic model concluded that is the constituent particle of all kinds of atom. A . electron B. protron c. neutron D. None of these |
11 |
| 1352 | The kinetic energy of an electron accelerated from rest through a potential difference of 5V will be: A . ( 5 ~ J ) B. 5 erg ( c .5 e V ) D. ( 8 times 10^{-10} ) eV |
11 |
| 1353 | What is the lowest value of ( n ) that allows g orbitals to exist? |
11 |
| 1354 | What is the shape of f-orbital? A. spherical B. dumb bell c. double dumb bell D. no definite shape |
11 |
| 1355 | An odd electron molecule among the following is : A. ( C O ) в. ( S O_{2} ) ( c cdot C O_{2} ) D. ( N O ) E. ( O F_{2} ) |
11 |
| 1356 | State True or False. Electron was discovered by Goldstein. A. True B. False |
11 |
| 1357 | Matter is composed of: A. atoms B. molecules C . tiny particles D. all of the above |
11 |
| 1358 | The velocities of two particles ( A ) and ( B ) are 0.05 and ( 0.02 m s^{-1} ) respectively. The mass of ( B ) is five times the mass of A. The ratio of their de-Broglie’s wavelength is : A .2: 1 B. 1: 4 ( c cdot 1: 1 ) D. 4: 1 |
11 |
| 1359 | From the ( alpha ) -particle scattering experiment, Rutherford concluded that: This question has multiple correct options A. ( alpha ) -particles can approach within a distance of the order of ( 10^{-14} mathrm{m} ) of the nucleus B. the radius of the nucleus is less than ( 10^{-14} m ) C . scattering follows Coulomb’s law D. the positively charged parts of the atom move with extremely high velocities |
11 |
| 1360 | According to JJ Thomson’s atomic model, negative charges are embedded in: A. a lump of positive charge B. a lump of neutral particles c. alump of small atoms D. the nucleus |
11 |
| 1361 | The highest energy in Balmer series, in the emission spectra of hydrogen is represented by: ( left(R_{H}=109737 mathrm{cm}^{-1}right) ) ( mathbf{A} cdot 4389.48 mathrm{cm}^{-1} ) в. ( 2194.74 mathrm{cm}^{-1} ) c. ( 5486.85 mathrm{cm}^{-1} ) D. 27434.25cm” |
11 |
| 1362 | The energy of an electron in H atom is ( -3.4 e V . ) If the angular momentum of the electron is ( x times 10^{-34} J sec ^{-1}, ) then ( x ) is: A . 2.3 B. 2.1 c. 3. D. 3.3 |
11 |
| 1363 | What the movement of solid particles caused by collisions with the constantly moving molecules of a gas is called? | 11 |
| 1364 | 72. When photons of wavelength 2, are incident on an isolated sphere suspended by an insulated thread, the corresponding stopping potential is found to be V. When photons of wavelength are used, the corresponding stopping potential was thrice the above value. If light of wavelength is is used, calculate the stopping potential for this case. |
11 |
| 1365 | The energy of an electron in the first Bohr orbit of H atom is -13.6e ( V ). The possible energy value(s) of the excited state for electrons in Bohr orbits of ( L i^{2+} ) is: A. ( -61.2 e V ) B. ( -13.6 e V ) c. ( -122.4 e V ) D. ( +6.8 e V ) |
11 |
| 1366 | What do you think would be the observation if the ( alpha ) -particle scattering experiment is carried out using a foil of a metal other than gold? A. ( alpha ) particles would deflect by the foil by large angles B. Most of the fast moving ( alpha ) particles would not pass straight through the metal foil c. There would be no change in the observation D. All particles would appear rebound |
11 |
| 1367 | Which have the same number of ( s ) – electrons as the ( d ) -electrons in ( F e^{2+} ? ) ( mathbf{A} cdot L i ) в. ( N a ) ( c cdot N ) D. ( P ) |
11 |
| 1368 | Which orbital has two angular nodal planes ? ( A cdot s ) B. ( p ) ( c cdot d ) D. ( f ) |
11 |
| 1369 | A sample of H-atoms containing all the atoms in some excited state is irradiated with light of wavelength ( lambda ) and the atoms get re-excited to further higher orbit. On removing the light source, atoms de-excite to ground state with emission of radiations. The emission spectrum thus obtained consists of ten spectral lines corresponding to ten different wavelengths. Out of the ten spectral lines, seven lines have the wavelength smaller than the incident llambda, while only two of them have wavelengths longer than the incident wavelength. The orbit number in which electrons were present initially is: A. 3 B. 4 ( c cdot 5 ) ( D .6 ) |
11 |
| 1370 | There is a stream of neutrons with a kinetic energy of ( 0.0327 mathrm{eV} ). If the half- life of neutrons is 700 second, the percentage fraction of neutron will decay before they travel a distance of 10 ( mathrm{km} ) is (multiply answer by 20). (mass of neutron ( =1.675 times ) ( left.10^{-27} k gright) ) |
11 |
| 1371 | The number of lobes in most of the ( d ) orbits are: A. 6 B. 10 ( c cdot 8 ) D. 4 |
11 |
| 1372 | The triad of nuclei that is isotonic is: ( mathbf{A} cdot_{6}^{14} C, frac{15}{7} N,_{9}^{17} F ) В . ( _{6}^{12} C, frac{14}{7} N, ) ‘ ( _{19}^{9} F ) ( mathbf{C} cdot_{6}^{14} C, frac{14}{7} N,_{9}^{17} F ) ( mathbf{D} cdot_{6}^{14} C, frac{14}{7} N, frac{19}{9} F ) |
11 |
| 1373 | Which of the following ions has the maximum magnetic moment? ( mathbf{A} cdot M n^{+2} ) B. ( F e^{+2} ) ( c cdot T i^{+2} ) D. ( C r^{+2} ) |
11 |
| 1374 | The particles present in the nucleus of an atom are : A. the proton and the electron B. the electron and the neutron c. the proton and the neutron D. none of these |
11 |
| 1375 | Calculate (a) frequency and (b) wave- number of yellow radiation having wavelength ( 5800 A ) |
11 |
| 1376 | The difference between the mass number and the atomic number gives the A. number of neutrons B. number of electrons c. charge of an element D. number of protons |
11 |
| 1377 | Scientist previously thought an atom looked like plum pudding. In this model, it was assumed that protons and electrons were distributed throughout the atom almost randomly. Which of the following contributions DISPROVED the Plum Pudding model? A. Rutherford’s Gold Foil Experiment. B. J.J. Thomson’s Cathode Ray Experiment. c. Millikan’s Oil Drop Experiment D. Bohr’s Model of the Atom. |
11 |
| 1378 | What element has a H-like spectrum, whose lines have wavelengths four times shorter than those of atomic hydrogen? A . не B . ( mathrm{He}^{+} ) ( c cdot H ) ( D cdot L i^{2} ) |
11 |
| 1379 | Name the group of lines in the visible region of the hydrogen spectrum. | 11 |
| 1380 | The energy released during the transition of ( 3^{r d} ) orbit to ( 2^{n d} ) orbit is equal to the difference of energy of the two levels. A. True B. False |
11 |
| 1381 | A) Rutherford’s alpha parcticle scattering experiment led to the discovery of the B) Isotopes have same but different C) Neon and chlorine have atomic numbers 10 and 17 respectively. Their valencies will be and D) An atom with 3 protons and 4 neutrons will have a valency of |
11 |
| 1382 | The number of lobes in most of the d- orbitals are: A. 6 B. 8 c. 10 ( D ) |
11 |
| 1383 | The number of quantum numbers required for the designation of an orbital in an atom is: ( A ) B. 2 ( c cdot 3 ) D. 4 |
11 |
| 1384 | Alveoli ane the tiny sacks of air in lungs whose average diameter is ( 5 times 10^{-5} mathrm{m} ) Consider a oxygen molecule ( (5.3 times ) ( mathbf{1 0}^{-mathbf{2 6}} mathbf{k g} ) ) trapped within a sec Calculate uncertainty in velocity of oxygen molecule. A ( cdot 1.98 times 10^{-5} m s^{-1} ) В . ( 2 times 10^{-8} mathrm{ms}^{-1} ) ( mathbf{c} cdot 5 times 10^{-5} m s^{-} ) D. ( 3 times 10^{-8} mathrm{ms}^{-1} ) |
11 |
| 1385 | Which of the following pairs constitute isotones? A ( cdot frac{i 3}{6} mathrm{C} ) and ( frac{14}{6} mathrm{C} ) B . ( _{6}^{13} C ) and ( frac{14}{7} N ) C ( cdot frac{44}{7} N ) and ( _{9}^{19} F ) D. ( frac{14}{7} N ) and ( frac{15}{7} N ) |
11 |
| 1386 | (a) PE decreases, TE decreases 10. If the electron in an hydrogen atom jumps from an orbit with level ny = 3 to an orbit with level n = 2, the emitted radiation has a wavelength given by . 36 (a) 1 = (b) 2 = 5R (c) 2 = (d) a= |
11 |
| 1387 | After ( n p ) -orbitals are filled, the next orbital filled will be: A ( cdot(n+1) s ) B ( cdot(n+2) p ) ( mathbf{c} cdot(n+1) d ) D. ( (n+2) s ) |
11 |
| 1388 | Assertion According to de Broglie, the wavelengths associtated with electrons and other subatomic particles can be detected experimentally. Reason The wavelength associated with any material particle is directly proportional to its mass. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 1389 | In 1911 came to the conclusion that the atom had a dense nucleus because most of the particles shot straight through, but some of the particles were deflected due to the dense nucleus of the gold atoms. A. Thompson B. Chadwick c. Rutherford D. none of the above |
11 |
| 1390 | In a photoemissive cell with executing wavelength ( lambda ), the fastest electron has to speed v. If the exciting wavelength is changed to ( frac{3 lambda}{4}, ) the speed of the fastest emitted electron will be: ( ^{mathrm{A}} vleft(frac{3}{4}right)^{1 / 2} ) в. ( _{v}left(frac{4}{3}right)^{1 / 2} ) ( ^{mathrm{c}} cdot operatorname{lessthan} vleft(frac{4}{3}right)^{1 / 2} ) D. greater than ( vleft(frac{4}{3}right)^{1 / 2} ) |
11 |
| 1391 | The wavelength of light is 8000 A. The no. of photon required to provide 20 J of energy is approximately: A ( cdot 4.56 times 10^{18} ) B . ( 8 times 10^{19} ) c. ( 7 times 10^{19} ) D. ( 4 times 10^{7} ) |
11 |
| 1392 | The atomic weight of Ne is 20.2. Ne is mixture of ( N e^{20} ) and ( N e^{22} . ) The relative abundance of the heavier isotope is: A . ( 90 % ) B. 20% c. ( 40 % ) D. ( 10 % ) |
11 |
| 1393 | Which of the following conclusions cannot be drawn on Rutherford’s atomic model? A. The total mass of an atom is concentrated at the centre of the atom B. Nucleus is located inside the atom containing positively charged particles C. Most of the atom is empty in space D. Electrons revolve around the nucleus in stationary, circular orbits |
11 |
| 1394 | Which one has the electronic configuration given below? ( 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{1} ) A . ( N a^{+} ) в. ( A l ) ( c . F ) D. ( T i ) E . ( B r ) |
11 |
| 1395 | Emission transitions in the Paschen series end at orbit ( n=3 ) and start from orbit ( n ) and can be represented as ( v= ) ( mathbf{3} . mathbf{2 9} times mathbf{1 0}^{mathbf{1 5}}(mathbf{H z})left[mathbf{1} / mathbf{3}^{mathbf{2}}-mathbf{1} / mathbf{n}^{mathbf{2}}right] ) Calculate the value of ( n ) if the transition is observed at 1.285 nm. Find the region of the spectrum. |
11 |
| 1396 | Find the number of photons of radiation of frequency ( 5 times 10^{13} s^{-1} ) that must be absorbed in order to melt one gm ice when the latent heat of fusion of ice is ( mathbf{3 3 0} mathbf{J} cdotleft(mathbf{h}=mathbf{6 . 6} times mathbf{1 0}^{-mathbf{3 4}} mathbf{J} times mathbf{s e c} .right) ) |
11 |
| 1397 | Uncertainity in position of a particle of ( 25 mathrm{g} ) in space is ( 10^{-15} mathrm{m} . ) Determine uncertainity in velocity ( left(mathrm{m} mathrm{sec}^{-1}right) ) in it. (plank’s constant, ( boldsymbol{h}=mathbf{6 . 6} times mathbf{1 0}^{-mathbf{3 4}} mathbf{J s} ) ) A . ( 2.1 times 10^{-18} ) В. ( 1.2 times 10^{-18} ) c. ( 1.8 times 10^{-18} ) D. ( 2.5 times 10^{-18} ) |
11 |
| 1398 | An atom of an element contains 29 electrons and 35 neutrons. Deduce (i) the number of protons and (ii) the electronic configuration of the element. |
11 |
| 1399 | State True or False. Hydrogen atom can produce single spectral line due to a presence of one electron. A. True B. False |
11 |
| 1400 | The configuration ( 1 s^{2} 2 s^{2} 2 p^{5} 3 s^{1} ) shows: A. excited state of ( O_{2}^{-} ) B. excited state of neon atom c. excited state of fluorine atom D. ground state of fluorine atom |
11 |
| 1401 | The electron present in the 5th orbit in an excited hydrogen atom returns back to the ground state. The number of lines which appear in Lyman series of hydrogen spectrum is: A . 5 B. 10 ( c cdot 4 ) D. 6 |
11 |
| 1402 | The maximum probability of finding electron in the ( d_{x y} ) orbital is A. Along with ( x ) – axis B. Along the ( y ) – axis C. At an angle of ( 45^{0} ) from the ( X ) and Y axis D. At an angle of ( 90^{0} ) from the ( x ) and ( y ) axis |
11 |
| 1403 | How much energy is required to ionise ( mathrm{H} ) atom if the electron occupies ( n=5 ) orbits? Compare your answer with the ionization enthalpy of H atom [ energy required to remove the electron from ( n=1 text { orbit }] ) | 11 |
| 1404 | Which statement about a ( 3 p ) orbital is correct? A. It can hold a maximum of 6 electrons B. It has the highest energy of the orbitals with principal quantum number 3 C. It is at a higher energy level than a 3 s orbital but has the same shape D. It is occupied by one electron in an isolated phosphorous atom |
11 |
| 1405 | Assertion An element (X) with an atomic number of 16 has 14 electrons in ( X^{2-} ) Reason Two protons bind the two outermost electrons A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
11 |
| 1406 | Containers ( X, Y ) and ( Z ) of the equal volume contain oxygen, neon and methane respectively at the same temperature and pressure. The correct increasing order of their masses is: A. ( X<Y<Z ) в. ( Y<Z<X ) c. ( Z<X<Y ) D. ( Z<Y<X ) |
11 |
| 1407 | Match the pairs. | 11 |
| 1408 | Which of the following transition in ( H e^{+} ) ion emits light of wavelength equal to the longest wavelength emitted in the Paschen series H-atom? ( mathbf{A} cdot 9 rightarrow 6 ) B . ( 8 rightarrow 6 ) c. ( 8 rightarrow 4 ) D. none of these |
11 |
| 1409 | If spin quantum number are ( -frac{1}{2}, 0,+frac{1}{2} ) based on the above assumption electronic configuration of the elements with atomic number 30 is: B . ( 1 s^{3} 1 p^{15} 2 s^{3} 1 d^{9} ) C ( cdot 1 s^{9} 1 p^{15} 2 s^{6} ) D cdot ( 1 s^{3} 19^{p} 2 s^{3} 2 p^{9} 1 d^{6} ) |
11 |
| 1410 | Charge on electron of mass ( 9.109 times ) ( 10^{-31} mathrm{Kg} ) is: A ( cdot 1.603 times 10^{-19} mathrm{C} ) В. ( -1.603 times 10^{-19} mathrm{C} ) c. ( 9.109 times 10^{-31} mathrm{C} ) D. ( -9.109 times 10^{-31} mathrm{C} ) |
11 |
| 1411 | Isotopes of cobalt ( ldots ) used in the treatment of cancer A. ( C o-59 ) в. ( C o-60 ) c. ( C o-61 ) D. ( C o-62 ) |
11 |
| 1412 | The de-brogile wavelength of an electron in the ground state of hydrogen atom is: ( [boldsymbol{K} . boldsymbol{E} .=mathbf{1 3 . 6} e boldsymbol{V} ; mathbf{1} e boldsymbol{V}=mathbf{1 . 6 0 2} times ) ( mathbf{1 0}^{-mathbf{1 9}} boldsymbol{J} ) A. ( 33.28 n m ) B. ( 3.328 n m ) ( mathbf{c} .0 .3328 n m ) D. ( 0.0332 n m ) |
11 |
| 1413 | 8. Consider a hydrogen like atom whose energy in n’hexicited 13.622 state is given by En=– when this excited atom makes a transition from excited state to ground state, most energetic photons have energy Emax = 52.224 eV and least energetic photons have energy Emin= 1.224 eV. The atomic number of atom is (a) 2 (b) 5 (c) 4 (d) None of these |
11 |
| 1414 | Which one of the following corresponds to a photon of highest energy? A ( . lambda=300 n m ) В . ( v=3 times 10^{8} s^{-1} ) c. ( v=30 c m^{-1} ) D . ( varepsilon=6.626 times 10^{-27} J ) |
11 |
| 1415 | How to find atomic mass of any element, explain. |
11 |
| 1416 | An electron in ( 2^{n d} ) orbit gains energy and goes to ( 4^{t h} ) orbit. What are the difference in angular momentums experienced by the electron due to the transition? |
11 |
| 1417 | The cathode ray experiment is conducted in a discharge tube containing four different gases ( A, B, C ) and ( D, ) the molecular weight of ( A=B>D ) ( >mathrm{C}, ) then ( mathrm{e} / mathrm{m} ) as observed will be: ( A cdot A>B>D>C ) B. ( A<D<Bmathrm{D}>mathrm{C} ) D. ( A=B=C=D ) |
11 |
| 1418 | Cathode rays travel in A. waves B. packets c. straight lines D. alternative waves |
11 |
| 1419 | USIC UL SCICU U N CICLE IL 10 TELLICOLTTUU UC UCICUS. Q64. Among the following pairs of orbitals, which orbital will experience more effective nuclear charge? (0) 2s and 3s (ii) 4d and 4f (iii) 3d and 3p? Caltabil |
11 |
| 1420 | Q1. Give the relation between welength and momentum of moving microscopic particle. What is the relation known as? |
11 |
| 1421 | An experiment requires minimum ( beta ) activity produced at the rate of ( 346 beta ) particles per minute. The half-life period of ( _{42}^{99} ) Mo which is a ( beta ) -emitter is 66.6 hr. The minimum amount of ( _{42}^{99} ) Mo required to carry out the experiment in 6.909 hour is : A ( cdot 6.78 times 10^{-16} g ) В. ( 3.52 times 10^{-16} g ) c. ( 5.21 times 10^{-16} g ) D. none of these |
11 |
| 1422 | Which of the following is true regarding an Ne atom with a mass number of 20 and an ( O^{2-} ) ion with a mass number of ( 16 ? ) A. The contain the same number of protons B. The contain the same number of neutrons C. The contain the same number of protons plus neutrons D. They are isoelectronic. E. They are isomers |
11 |
| 1423 | Write electronic configurations of the elements with atomic number 17. | 11 |
| 1424 | Boron can not form more than 4 bonds because: This question has multiple correct options A. of unavailability of d-orbitals B. of unavailabilty of empty p-orbitals C. Boron is so smaller D. it does not have more valence electrons |
11 |
| 1425 | The ions ( N^{3-}, O^{2-}, F^{-}, N a^{+}, M g^{2+} ) are isoelectronic. Their ionic radii shows: A. an increase from ( N^{3-} ) to ( F^{-} ) and then decrease from ( N a^{+} ) to ( M g^{2+} ) B. a decrease from ( N^{3-} ) to ( F^{-} ) and then increase from ( N a^{+} ) to ( M g^{2+} ) C . a significant increase from ( N^{3-} ) to ( M g^{2+} ) D. a significant decrease from ( N^{3-} ) to ( M g^{2+} ) |
11 |
| 1426 | The orbital angular momentum of an electron in 2 s orbitals is: A ( cdot+frac{1}{2} frac{h}{2 pi} ) B. zero ( c cdot frac{h}{2 pi} ) D. ( sqrt{2} frac{h}{2 pi} ) |
11 |
| 1427 | If the radius of first Bohr orbit is ( x p m ) then the radius of the third orbit would be: в. ( (6 times x) ) рт C ( cdotleft(frac{1}{2} times xright) p m ) D. ( (9 times x) p m ) |
11 |
| 1428 | Which of the following nuclei is unstable? ( mathbf{A} cdot_{5} B^{10} ) B. ( _{4} B e^{10} ) ( mathrm{c} cdot_{7} N^{14} ) ( mathrm{D} cdot_{8} mathrm{O}^{1} ) |
11 |
| 1429 | 45. In hydrogen and hydrogen-like atoms, the ratio of E4n – E2n and E2n – En varies with atomic number z and principal quantum number n as (b) ? (d) none of these |
11 |
| 1430 | Which of the following statements given below is incorrect? A. ( O N F ) is isoelectronic with ( O_{2} N^{-} ) B. ( O F_{2} ) is an oxide of fluorine c. ( C l_{2} O_{7} ) is an anhhydride of perchloric acid D. ( O_{3} ) molecule is bent. |
11 |
| 1431 | An electron in the hydrogen atom is excited from ( 1^{s t} ) orbit to ( 5^{t h} ) orbit. The frequency of radiation is: A ( cdot 0.44 times 10^{-9} mathrm{Hz} ) В. ( 3.15 times 10^{15} mathrm{Hz} ) c. ( 6.2 times 10^{8} mathrm{Hz} ) D. ( 1.13 times 10^{-12} mathrm{Hz} ) |
11 |
| 1432 | Elements ( A, B, C, O ) and ( E ) having the following electronic configuration (i) ( 1 s^{2}, 2 s^{2}, 2 p^{1} ) (ii) ( 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2}, 3 p^{1} ) (iii) ( 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2}, 3 p^{3} ) (iv) ( 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2}, 3 p^{5} ) ( (v) 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2}, 3 p^{6} ) Electronic configurations belonging to the same group are: A. (i) and (iii) B. (i) and (iv) c. (i) and (ii) D. (i) and (v) |
11 |
| 1433 | Which of the following have highest energy of electron? ( mathbf{A} cdot_{1} H^{1} ) В . ( _{1} H^{2} ) ( mathbf{c} cdot_{1} H^{3} ) D. All have equal energy |
11 |
| 1434 | The quantum yield for decompostion of ( H I ) is 0.2 In a experiment 0.01 moles of ( H I ) are decomposed. Find the number of photons absorbed. ( left(N_{A}=6 times 10^{23}right) ) |
11 |
| 1435 | ( frac{sqrt{6}}{frac{1}{4}} ) | 11 |
| 1436 | Isotopes are atoms with the same number of protons, but differing numbers of neutrons. Isotopes are different forms of a single element. A. True B. False |
11 |
| 1437 | In which element rule(c) (i) is followed? A ( cdot 29^{c} ) B. 24 ( ^{c} ) ( c cdot 26^{F e} ) D. ( 25^{M n} ) |
11 |
| 1438 | In the uranium radioactive series the initial nucleus is ( _{92}^{238} mathrm{U} ) and the final nucleus is ( _{82}^{206} ) Pb. When the uranium nucleus decays to lead, number of ( alpha ) particles emitted is and the number of ( beta ) -particles emitted is |
11 |
| 1439 | Consider the hydrogen atom to be a proton embedded in a cavity of radius ( a_{0} ) (Bohr’s radius), whose charge is neutralized by the addition of an electron to the cavity in vacuum, infinitely slowly. Then the wavelength of the electron when it is at a distance of ( a_{0} ) from the proton will be A ( cdot lambda=sqrt{frac{4 pi varepsilon_{0} a_{0}}{h^{2} e^{2} m}} ) B. ( lambda=sqrt{frac{4 pi varepsilon_{0} a_{0} h^{2}}{e m}} ) ( ^{mathbf{c}} cdot_{lambda}=sqrt{frac{4 pi varepsilon_{0} a_{0} h^{2}}{e^{2} m}} ) D. ( lambda=sqrt{frac{4 pi varepsilon_{0} a_{0} h^{2}}{e^{5} m}} ) |
11 |
| 1440 | Bohr’s model could not explain the of multi electron species. A. spectra B. nucleus c. spin D. orbital |
11 |
| 1441 | If the energy difference between two electronic states is 46.12 kcal/mol; What will be the frequency of light emitted when the electrons dropped from higher to lower states ( (N h= ) ( 9.52 times 10^{-14} ) kcal sec mol ( ^{-1} ) ) where ( N ) is the Avogadro number |
11 |
| 1442 | Give the equation which explains the different series of lines in the atomic spectrum of hydrogen. who is the equation named after? Explain the various terms involved. |
11 |
| 1443 | Dual character of an electron was explained by: A. Bohr B. Heisenberg c. De Broglie D. Pauli |
11 |
| 1444 | 15. The first line in the Lyman series has wavelength 2. The wavelength of the first line in Balmer series is (b)2 |
11 |
| 1445 | Boron has two isotopes ( mathrm{B}-10 ) and ( mathrm{B}-11 . ) I the average atomic mass of boron is 10.80 u. What is the percentage of a heavier isotope? A. 80 B. 20 ( c . ) 30 D. 70 |
11 |
| 1446 | The disintegration energy ( Q ) for the change ( _{Z}^{A} mathbf{X} stackrel{-alpha}{longrightarrow} underset{Z-2}{A-4} mathbf{D}+Q ) is given by ( boldsymbol{Q}=left[boldsymbol{M}left(begin{array}{l}A mathbf{X} \ Zend{array}right)-boldsymbol{M}left(begin{array}{l}boldsymbol{A}-mathbf{4} \ boldsymbol{Z}-mathbf{2}end{array} mathbf{D}right)-right. ) ( left.Mleft(_{2}^{4} mathbf{H e}right)right] C^{2}, ) where ( M ) represents the mass of respective nuclei reported in paranthesis and ( C ) is speed of light. For ( alpha ) -decay : A. ( Q=+v e ) В. ( Q=-v e ) c. ( Q=0 ) D. not related with ( Q ) |
11 |
| 1447 | Which of the following is not the property of cathode rays: – A. It produces heating effect B. It does not deflect in electric field c. It casts shadow D. It produces flurosence |
11 |
| 1448 | What are the limitations of J.J.Thomson’s model of the atom? |
11 |
| 1449 | Select a lustrous material out of the following substances. Gold, Sand, Silver, Rubber |
11 |
| 1450 | ‘n spectrum corresponds to the … This series lies in the visible 0.32 The Balmer series in the hydrogen spectrum transition from n = 2 to n = 3, 4, ….. This senes region. Calculate the wave number of line associated in Balmer series when the electron moves to n = 4 orbit. (Rx = 109677 cm-2) |
11 |
| 1451 | If ( E_{1}, E_{2} ) and ( E_{3} ) represent respectively the kinetic energies of an electron, an alpha particle and a proton each having same de Broglie wavelength then: A. ( E_{1}>E_{3}>E_{2} ) в. ( E_{2}>E_{3}>E_{1} ) c. ( E_{1}>E_{2}>E_{3} ) D. ( E_{1}=E_{2}=E_{3} ) |
11 |
| 1452 | Assertion The ratio of radius of first orbit to second orbit of hydrogen atom is 1: 4 Reason Radius for each circular orbit ( = ) ( mathbf{0 . 5 2 9} boldsymbol{n ^ { 2 }} boldsymbol{hat { A }} ) A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion. B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
11 |
| 1453 | 60. If wavelength of photon emitted due to transition of an electron from the third orbit to the first orbit in a hydrogen atom is 2, then the wavelength of photon emitted due to transition of electron from the fourth orbit to the second orbit will be 11 |
11 |
| 1454 | Electrons are present in the nucleus of an atom. A . True B. False |
11 |
| 1455 | ( alpha- ) particles can be detected using : A. thin aluminium sheet B. barium sulphate c. zinc sulphide screen D. gold foil |
11 |
| 1456 | 34. The wavelength of the first line of Lyman series in hydrogen atom is 1216. The wavelength of the first line of Lyman series for 10 times ionized sodium atom will be added (a) 0.1 Å (b) 1000 Å (c) 100 Å (d) 10 Å |
11 |
| 1457 | Which of the following is a state of matter? A. Quark-gluon plasma B. Quantum spin liquid c. superfluid D. All of above |
11 |
| 1458 | Uncertainly principle is valid for: A. Proton B. Methane C. Both (proton) and (methane) D. ( 1 mu m ) sized platinum particles E . ( 1 mu m ) sized ( N a C l ) particles |
11 |
| 1459 | ( boldsymbol{H}_{alpha} ) line of Balmer series is ( mathbf{6 5 0 0} boldsymbol{A} ). The wave length of ( boldsymbol{H} gamma ) is? A. ( 4815 AA ) в. 4298 А c. ( 7800 hat{h} ) D. 3800 月 |
11 |
| 1460 | The atomic weight of an atom is because of A. electrons and protons B. electrons and neutrons c. neutrons and protons D. electrons, neutrons and protons |
11 |
| 1461 | Identify the error(s) in the orbital notation diagram for oxygen in the in the image ( a ) a. ( prod_{1 mathrm{s}} frac{|uparrow downarrow|}{2 mathrm{s}} frac{|uparrow| downarrow|uparrow|}{2 mathrm{p}} ) ( frac{sqrt{11}}{1 mathrm{s}} frac{sqrt{11}}{2 mathrm{s}} frac{sqrt{mathrm{t}} uparrow 1}{2 mathrm{p}} ) e. ( frac{sqrt{uparrow} mid}{1 s} ) [ frac{|uparrow| uparrow|uparrow|}{2 p} ] This question has multiple correct options A. The electrons are not drawn with the appropriate spins B. This is not a picture of oxygen. It is nitrogen c. The electrons are not filled out according to Aufbau’s’s Principle D. The electrons are not filled out according to Hund’s Rule |
11 |
| 1462 | Choose the correct statement among the following. This question has multiple correct options A. Radial distribution function ( mathbf{B} cdotleft(Psi^{24 pi^{2}} d rright) ) C ( . Psi(r) Psi(theta) Psi(Phi))=Psi(x / y / z) ) is independent of ( theta ) and ( phi ) D. ‘2p’orbital with quantum numbers.n=2,|=1,m=0,also shows angular dependence |
11 |
| 1463 | How long will it take a radiowave of frequency ( 6 times 10^{3} s^{-1} ) to travel from one place to other? The distance is ( 10^{14} k m ) |
11 |
| 1464 | Electrons are represented as: ( mathbf{A} cdot e ) B ( cdot e^{-} ) ( mathbf{c} cdot e^{+} ) ( mathrm{D} cdot e^{+} ) |
11 |
| 1465 | When an electron is transferred in hydrogen atom from ( n=4 ) orbit to ( n=5 ) orbit to which spectral series does this belong? |
11 |
| 1466 | In the emission line spectra of hydrogen atom, how many lines can be accounted for by all possible electron transitions between five lowest energy levels within the atom? ( A cdot 4 ) B. 5 c. 10 D. 20 |
11 |
| 1467 | Which of the following is true for Thomson’s model of the atom? A. The radius of an electron can be calculated using Thomson’s model B. In an undisturbed atom, the electrons will be at their equilibrium positions, where the attraction between the cloud of positive charge and the electrons balances their mutual repulsion C. When the electrons are disturbed by collision, they will vibrate around their equilibrium positions and emit electromagnetic radiation whose frequency is of the order of magnitude of the frequency of electromagnetic radiation of a vibrating electron D. Both (B) and (C) |
11 |
| 1468 | A radioactive atom ( _{Y}^{X} M ) emits two ( alpha^{-} ) particles and one ( beta ) -particle respectively. The number of neutrons in the product nucleus will be : ( mathbf{A} cdot X-Y-4 ) B. ( X-5-Y ) c. ( X-3-Y ) D. ( X-Y-6 ) |
11 |
| 1469 | The highest value of ( e / m ) of anode rays has been observed when the discharge tube is filled with: A. nitrogen B. oxygen c. hydrogen D. helium |
11 |
| 1470 | u + (0) 04 21. The orbital velocity of an electron in the ground sta v. If the electron is excited to energy state -0.54 eV orbital velocity will be (a) v |
11 |
| 1471 | The reaction; ( mathbf{9 2} boldsymbol{U}^{mathbf{2 3 8}}+mathbf{0} boldsymbol{n}^{mathbf{1}} rightarrow mathbf{9 2} boldsymbol{U}^{mathbf{2 3 9}} rightarrow mathbf{9 3} boldsymbol{N} boldsymbol{p}^{mathbf{2 3 9}}+ ) ( -1 e^{0} ) is an example of: A. ( alpha ) -emission B. ( beta ) -emission C ( . gamma ) -emission D. none of these |
11 |
| 1472 | The conclusion of Rutherford from his ( alpha ) -ray scattering experiment is: A. many particles were deflected from their path, indicating that the positive charge of the atom occupies very small space. B. many particles were deflected from their path, indicating that the positive charge of the atom occupies very large space. C. most of the space inside the atom is empty because most of the ( alpha ) -particles passed through the gold foil without getting deflected. D. a very large fraction of alpha-particles were deflected by ( 180^{circ} ), indicating that all the positive charges and mass of the gold atom were concentrated in a very small volume within the atom |
11 |
| 1473 | At what velocity ratio ( frac{v_{e}}{v_{p}} ) are the wavelengths of an electron and a proton equal? ( left(boldsymbol{m}_{e}=mathbf{9 . 1} times mathbf{1 0}^{-mathbf{2 8}} boldsymbol{g} quad boldsymbol{text {and}} quad boldsymbol{m}_{boldsymbol{p}}=mathbf{1 . 6 7}right. ) A. ( 1.2 times 10^{3} ) В. ( 1.8 times 10^{3} ) c. ( 2.4 times 10^{3} ) D. ( 1.6 times 10^{3} ) |
11 |
| 1474 | The number of lines of atomic hydrogen spectrum fall within the wavelength range from 94.5 to 130.0 nm is: |
11 |
| 1475 | Neutron has a ( _{-1-} ) charge A ( cdot ) tve B. -ve c. zero D. None of these |
11 |
| 1476 | Assertion The radial probability distribution curves of ( 1 s, 2 p, 3 d- ) orbitals are identical in shape. Reason The number of nodal planes present in these orbitals are different. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect and Reason are correct |
11 |
| 1477 | If the lowest energy X-rays have ( lambda= ) ( 3.055 times 10^{-8} m, ) estimate the minimum difference in energy between two Bohr’s orbits such that an electronic transition would correspond to the emission of an X-ray. Assuming that the electrons in other shells exert no influence, at what ( Z(text { minimum }) ) would a transition from a second energy level to the first result in the emission of an X-ray? ( mathbf{A} cdot mathbf{1} ) B. 2 ( c cdot 3 ) D. 4 |
11 |
| 1478 | Find the frequency of light that corresponds to photons of energy ( 5.0 times ) ( 10^{-5} ) erg. ( mathbf{A} cdot 7.5 times 10^{-21} sec ^{-1} ) В. ( 7.5 times 10^{-21} ) sec c. ( 7.5 times 10^{21} ) sec ( ^{-1} ) D. ( 7.5 times 10^{2} ) sec |
11 |
| 1479 | The isoelectronic set of ions is: A ( cdot N^{3-}, L i^{+}, M g^{2+} ) and ( O^{2-} ) B. ( L i^{+}, N a^{+}, O^{2-} ) and ( F^{-} ) c. ( F^{-}, L i^{+}, N a^{+} ) and ( M g^{2} ) D. ( N^{3},, O^{2-}, F^{-} ) and ( N a^{+} ) |
11 |
| 1480 | Thomson’s model of atom is also known as: This question has multiple correct options A. water-melon model B. raisin pudding model c. plum pudding model D. Rutherford’s model |
11 |
| 1481 | In hydrogen atomic spectrum, a series limit is found at ( 12186.3 mathrm{cm}^{-1} ). Then it belongs to : A. Lyman series B. Balmer series c. Paschen series D. Brackett series |
11 |
| 1482 | Identify the sets of electronic transitions associated with release of energy and absorption of energy. ( A cdot n=4 ) to ( n=1 ; n=2 ) to ( n=1 ) B. ( n=4 ) to ( n=3 ; n=4 ) to ( n=2 ) ( c cdot n=3 ) to ( n=5 ; n=2 ) to ( n=3 ) D. ( n=3 ) to ( n=2 ; n=1 ) to ( n=2 ) |
11 |
| 1483 | The number of nodal planes in each ( boldsymbol{p} ) orbital ( mathbf{A} cdot mathbf{0} ) B. ( c cdot 2 ) D. 3 |
11 |
| 1484 | If the energy difference between the electronic states is ( 214.68 mathrm{kJ} mathrm{mol}^{-1} ) calculate the frequency of light emitted when an electron drops form the higher to the lower state Plank’s constant? ( h=39.79 times k J mathrm{mol}^{-1} ) A ( cdot 5.39 times 10^{14} ) cps B. ( 5.99 times 10^{15} ) cps C. ( 5.99 times 10^{14} ) cps D. 5.39 ( times 10^{15} mathrm{cps} ) |
11 |
| 1485 | 74. Making use of the uncertainty principle, evaluate the minimum permitted energy of an electron in a hydrogen atom and its corresponding apparent distance from the nucleus. |
11 |
| 1486 | How many of the following is the matter? Chair, Air, Heat, Smell, Sound, Almonds, Thought and Cold drink. ( A cdot 4 ) B. 5 ( c cdot 6 ) D. |
11 |
| 1487 | All the mass of the atom resides in the A. nucleus B. molecules ( c . ) ions D. orbit |
11 |
| 1488 | Which of the following is the most abundant isotope of chlorine? A. Chlorine -35 B. Chlorine – 35.45 c. Chlorine-36 D. Chlorine -37 |
11 |
| 1489 | For ( n=5, ) the types of orbitals found in shell is? ( A cdot s ) B. s, p ( c cdot s, p, d, f ) D. ( s, p, d, f, g ) |
11 |
| 1490 | The ratio of the radius of Bohr first orbit for the electron orbiting the hydrogen nucleus to that of the electron orbiting the deuterium nucleus (mass nearly twice that of nucleus) is approximately: A . 1: 1 B. 1: 2 c. 2: 1 D. 1: 4 |
11 |
| 1491 | The unpaired electrons in ( A l ) and ( S i ) are present in ( 3 p- ) orbital. Which electron will experience more effective nuclear charge from the nucleus? |
11 |
| 1492 | Which of the following series of transitions in the spectrum of hydrogen atom fall in visible region? A. Lyman series B. Balmer series c. Paschen series D. Brackett series. |
11 |
| 1493 | Through what potential difference must an electron pass to have a wavelength of ( mathbf{5 0 0} boldsymbol{A} ? ) A ( cdot 6.03 times 10^{-3} ) ev В. ( 3.01 times 10^{-4} mathrm{ev} ) ( c cdot 6.03 times 10^{-5} mathrm{ev} ) ( v ) D. ( 3.01 times 10^{-5} mathrm{ev} ) |
11 |
| 1494 | Magnesium hydroxide is the white milky substance in milk of magnesia. What mass of ( M g(O H)_{2} ) is formed when ( 15 m l ) of ( 0.2 M-N a O H ) is combined with ( 12 mathrm{ml} ) of ( 0.15 M- ) ( M g C l_{2} ? ) A. ( 0.087 g ) в. ( 0.079 g ) c. ( 0.1044 g ) D. ( 0.522 g ) |
11 |
| 1495 | The energy of the electron in the second and third Bohr orbits of the hydrogen atom is ( -5.42 times 10^{-12} ) erg and ( -2.41 times 10 ) -12 erg, respectively. The wavelength of the emitted radiation when the electron drops from third to second orbit is: A ( .4 .6 times 10^{6} ) B . ( 6.6 times 10^{3} ) c. ( 0.66 times 10^{6} ) D. none of these |
11 |
| 1496 | The value of Planck’s constant is ( 6.63 times 10^{34} mathrm{Js} . ) The speed of light is ( 3 times ) ( 10^{17} mathrm{nm} s^{1} . ) Which value is closest to the wavelength in nanometer of a quantum of light with a frequency of ( 6 times 10^{15} s^{1} ? ) A . 10 B. 25 ( c .50 ) D. 75 |
11 |
| 1497 | The difference in angular momentums associated with an electronic transition in hydrogen atom is equal to ( 3 h / 2 pi . ) The atom contains only ( mathrm{K}, mathrm{L}, mathrm{M} ) and ( mathrm{N} ) shells. Calculate the energies and radii associated with the orbits. A. -13.6 ev and 0.314 Angstrom, 0.08 eV and 8.48 Angstrom B. -13.6 eV and 0.529 Angstrom, – 0.08 eV and 8.48 Angstrom c. 13.6 ev and 0.529 Angstrom, 0.08 eV and 8.48 Angstromm D. 27.2 eV and 0.529 Angstrom, 0.08 eV and 8.48 Angstrom |
11 |
| 1498 | Calculate the number of electrons in sulphur atom having ( boldsymbol{n}+boldsymbol{l}=mathbf{3} ) ( A cdot 2 ) B. 4 ( c .6 ) D. |
11 |
| 1499 | Rutherford’s ( alpha ) -scattering experiment led to the following conclusions: A. atom has largely completely filled space B. the centre of the atom has negatively charged nucleus C. the size of the nucleus is very small as compared to the size of the atom D. electrons revolve around the proton |
11 |
| 1500 | Quantum numbers ( l=2 ) and ( m=0 ) represent which orbital? A ( cdot d_{x y} ) B. ( d_{x^{2}-y^{2}} ) ( c cdot d_{z} ) D. ( d_{x x} ) |
11 |
| 1501 | In a given electric field, ( beta- ) particles are deflected more than ( alpha- ) particles, inspite of ( alpha- ) particles having larger charge. A. True B. False |
11 |
| 1502 | Complete the following nuclear equation: ( _{26}^{69} mathrm{Fe} rightarrow beta+_{-}- ) ( mathbf{A} cdot_{25}^{58} mathrm{Mn} ) B . ( frac{58}{27} mathrm{Co} ) ( mathbf{C} cdot_{25}^{59} mathrm{Mn} ) ( D cdot frac{59}{27} mathrm{Co} ) E ( . begin{array}{c}60 mathrm{Mn} \ 25end{array} ) |
11 |
| 1503 | ( B e^{2+} ) is isoelectronic with which of the following ions? A . ( H^{+} ) B . ( L i^{+} ) ( c cdot N a^{+} ) D. ( M g^{2+} ) |
11 |
| 1504 | 4.16 ( g ) of ( B a C I_{2} ) contains ( 2.74 g ) of Ba. The atomic weight of Ba is nearly: A .137 B. 208 c. 67.3 D. 97.27 |
11 |
| 1505 | Which of the following is/are incorrect for Humphrey lines of hydrogen spectrum? This question has multiple correct options A ( cdot n_{2}=7 rightarrow n_{1}=2 ) В ( cdot n_{2}=10 rightarrow n_{1}=6 ) c. ( n_{2}=5 rightarrow n_{1}=1 ) D ( cdot n_{2}=11 rightarrow n_{1}=3 ) |
11 |
| 1506 | A particle ( X ) deflects towards negative plate in the presence of electric field. Identify the particle ( X ? ) A. Neutron B. Electron c. ( X ) -ray D. Proton |
11 |
| 1507 | The doubly ionized lithium atom is hydrogen-like with the atomic number ( z=3 . ) Find the wavelength of the radiation required to excite the electron in ( L i^{2+} ) from the first to the third Bohr orbit is: ( left[text { Given: } frac{1}{boldsymbol{R}_{boldsymbol{H}}}=mathbf{9 1 2} boldsymbol{A}right] ) ( mathbf{A} cdot 114 stackrel{circ}{A} ) B ( cdot 156^{circ} ) ( mathbf{c} cdot_{180 stackrel{circ}}{mathbf{h}} ) D ( cdot 201 stackrel{circ}{A} ) |
11 |
| 1508 | The atomic number of magnesium is 12 The number of protons in the nucleus of magnesium atom is: ( A cdot 6 ) B. 10 c. 12 D. 24 |
11 |
| 1509 | There have been certain objectives against food preservation by irradiations. These are: This question has multiple correct options A. irradiated food may itself become radioactive B. irradiation can destroy the the nutrients such as vitamins and amino acids C. ionising radiation produces reactive species such as the hydroxyl radical which then react with organic molecules to produce potentially harmful substances. D. irradiated food may be much costlier |
11 |
| 1510 | The number of unpaired electrons in ( M n^{4+}(z=25) ) is : A. four B. two c. five D. three |
11 |
| 1511 | Define nucleus. | 11 |
| 1512 | Q. 7 Two atoms are said to be isobars if (a) they have same atomic number but different mass number (b) they have same number of electrons but different number of neutrons (c) they have same number of neutrons but different number of electrons (d) sum of the number of protons and neutrons is same but the number of protons is different different |
11 |
| 1513 | Give graph is of which orbital? A ( .2 p ) в. 1 . ( c .2 s ) ( 0.3 s ) |
11 |
| 1514 | 79. The circumference of the second Bohr orbit of electron in hydrogen atom is 600 nm. The potential difference that must be applied between the plates so that the electrons have the de Broglie wavelength corresponding in this circumference is (a) 10-v (b) 2 x 10-V (c) 5 x 10-sv (d) 3 x 10-5 v |
11 |
| 1515 | Bohr’s model of an atom is contradicted by: A. Paulis exclusive principle B. Plancks quantum theory c. Heisenbergs uncertainty principle D. all the above |
11 |
| 1516 | Argon and calcium are isobar. Why? A. Both have same atomic number equal to 40 B. Both have different atomic mass C. Both have same atomic mass equal to 40 D. None of above |
11 |
| 1517 | The value of Planck’s constant is ( 6.63 times 10^{-34} J-s . ) The velocity of light is ( 3 times 10^{8} m / ) sec. Which value is closest to the wavelength in nanometer of a quantum of light with frequency of ( 8 times ) ( 10^{15} s e c^{-1} ? ) A ( .5 times 10^{-18} ) B . ( 4 times 10^{1} ) ( c cdot 3 times 10^{7} ) D. ( 2 times 10^{-25} ) |
11 |
| 1518 | The energy of an electron in the ( n^{t h} ) Bohr orbit of hydrogen atom is: A ( cdot frac{13.6}{n^{3}} e V ) В. ( -frac{13.6}{n^{3}} e V ) c. ( -frac{13.6}{n^{2}} e V ) D. ( -frac{13.6}{n} e V ) |
11 |
| 1519 | The colour of sky is due to: A. transmission of light B. wavelength of scattered light C. absorption of light by atmospheric gases D. all of these |
11 |
| 1520 | The elements ( ^{30} boldsymbol{S} boldsymbol{i}_{14},^{31} boldsymbol{P}_{15} ) and ( ^{32} boldsymbol{S}_{16} ) are called : ( A ). isotones B. isobars c. isotopes D. mirror nuclei |
11 |
| 1521 | The atoms of various isotopes of a particular element differ from each other in the number of: A. electrons in the outer shell only B. protons in the nucleus c. electrons in the inner shell only D. neutrons in the nucleus |
11 |
| 1522 | Kinetic energy of photoelectrons increases with increase in freqency of the light incident on the metal surface. A. True B. False |
11 |
| 1523 | Atomic number of Bismuth is: ( A cdot 84 ) B. 85 5 ( c cdot 83 ) D. 82 |
11 |
| 1524 | Estimate the difference in energy between I and II Bohr Orbit for a hydrogen atom. At what minimum at no a transition from ( n=2 ) to ( n=1 ) energy level would result in the emission of X-rays with ( lambda=3.0 x 10^{8} ) m? Which hydrogen like species does this at no correspond to |
11 |
| 1525 | In astronomical observations, signals observed from the distant stars are generally weak. If the photon detector receives a total of ( 3.15 times 10^{-18} J ) from the radiations of ( 600 mathrm{nm}, ) calculate the number of photons received by the detector. |
11 |
| 1526 | ( X ) is defined by the number of protons. What is ( X ? ) A. Cation B. Inert Gas c. crystal D. Anion E . Element |
11 |
| 1527 | The state or phase of a given set of matter can change depending on A. temperature B. pressure c. Both a and ( b ) D. None of above |
11 |
| 1528 | Calculate the wavelength of the first number of Balmer series of hydrogen spectrum (R for hydrogen ( =1.09678 times 10 ) ( left.7 m^{-1}right) ) A ( cdot 2188 times 10^{-10} mathrm{m} ) B. 656 ( times 10^{-10} mathrm{m} ) c. ( 6564 times 10^{-10} mathrm{m} ) D. None of these |
11 |
| 1529 | What is the wavelength (in ( n m ) ) of gamma-rays whose energy is 1.50 eV? A. ( 827.5 mathrm{nm} ) В. 627.5 nm c. ( 927.5 mathrm{nm} ) D. None of these |
11 |
| 1530 | Which of the following combinations give finally an isotope of the parent element? A. ( alpha, alpha, beta ) в. ( alpha, gamma, alpha ) c. ( alpha, beta, beta ) ( mathbf{D} cdot beta, gamma, alpha ) |
11 |
| 1531 | If an atom contains one electron and one proton, what charge will it carry? A. Positive B. Neutral c. Negative D. All of the above |
11 |
| 1532 | Of the following radiation emissions, which has no mass?? A. Alpha particle B. Beta particle c. Proton D. Neutron E. Gamma ray |
11 |
| 1533 | Which is not a correct order of energy for 1 st, 2 nd and 3 rd orbit? ( mathbf{A} cdot E_{1}>E_{2}>E_{3} ) ( mathbf{B} cdot(P E)_{1}<(P E)_{2}(K E)_{2}>(K E)_{3} ) D. A and C both |
11 |
| 1534 | Which of the following electron transitions in hydrogen atom will require largest amount of energy? A. From ( n=1 ) to ( n=2 ) B. From ( n=2 ) to ( n=3 ) c. From ( n=infty ) to ( n=1 ) D. From ( n=3 ) to ( n=5 ) |
11 |
| 1535 | The work function for a certain metal is 4.2 eV. Will this metal give photoelectric emission for incident radiation of wavelength 330 nm? |
11 |
| 1536 | The chloride of a solid metallic element contains ( 57.89 % ) by mass of the element. The specific heat of the element is 0.0324 cal ( d e g^{-1} g^{-1} ) Calculate the exact atomic mass of the element. |
11 |
| 1537 | 1. Cathode rays are deflected by (a) electric field only (c) magnetic field only (b) electric and magnetic field (d) none of these |
11 |
| 1538 | If one were to apply Bohr model to a particle of mass ‘ ( m^{prime} ) and charge ( ^{prime} q^{prime} ) moving in a plane under the influence of a magnetic field ( B ), the energy of the charged particle in the ( n^{t h} ) level will be: ( ^{A} cdot nleft(frac{h q B}{8 pi m}right) ) в. ( nleft(frac{h q B}{4 pi m}right) ) c. ( nleft(frac{h q B}{2 pi m}right) ) D. ( nleft(frac{h q B}{pi m}right) ) |
11 |
| 1539 | The energy required to break one mole of ( C l-C l ) bond in ( C l_{2} ) in ( 242 k J ) mol ( ^{-1} . ) The longest wavelength of light capable of breaking a single ( C l-C l ) bond is: ( left[c=3 times 10^{4} m s^{-1} text {and } N_{A}=6.02 timesright. ) ( left.10^{23} m o l^{-1}right] ) A. 594 nm B. 640 nm c. 700 nm D. 494 nm |
11 |
| 1540 | Assertion The specific charge of canal rays is not constant. Reason The mass of ion varies with speed. A. Assertion is correct but Reason is wrong. B. Assertion is wrong but Reason is correct. C. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion. D. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion |
11 |
| 1541 | Statement 1 The wavelenght equivalent of ( 1 mathrm{eV} ) is ( 1.24 times 10^{-6} ) metre and Statement 2: Electron volt is the energy imparted to an electron accelerated by a potential difference of 1 volt. A. Statement 1 is True, Statement 2 is True; statement 2 is correct explanation for statement 1 B. Statement 1 is True, Statement 2 is True; statement 2 is not a correct explanation for statement 1 c. Statement 1 is True, Statement 2 is False D. Statement 1 is False, Statement 2 is True |
11 |
| 1542 | Total energy of an electron in an atom is A. less than zero B. more than zero c. may be less or more than zero D. none of the above |
11 |
| 1543 | The angular momentum of an electron depends on: A. principal quantum number B. azimuthal quantum number c. magnetic quantum number D. all of the above |
11 |
| 1544 | Electrons are ejected from the metal when a light of certain frequency strikes the surface of a metal, This phenomenon is known as photoelectric effect and the ejected electrons are called photoelectrons.
If true then type ( 1, ) if false then type 0 |
11 |
| 1545 | Assertion Cathode rays are deflected towards positive plate in an electric field. Reason These consist of negatively charged particles. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
11 |
| 1546 | The minimum angular momentum that can be possessed by an electron in a hydrogen atom is: A ( cdot 2 times 10^{-34} operatorname{kg} m^{2} s^{-1} ) B. ( 1 times 10^{-34} mathrm{gm}^{2} mathrm{s}^{-1} ) C . ( 1 times 10^{-34} mathrm{kgm}^{2} mathrm{s}^{-1} ) D. none of these |
11 |
| 1547 | What is the mass of photon of sodium light having a wavelength of 5890 , i? ( left(text { Given } h=6.6 times 10^{-27} text {erg }-text { sec }right) ) ( mathbf{A} cdot 3.735 times 10^{-29} g ) В. ( 3.735 times 10^{-33} g ) c. ( 1.57 times 10^{-33} g ) D. ( 3.735 times 10^{-31} g ) |
11 |
| 1548 | An element has an atomic number 20 . How many electrons will be present in ( boldsymbol{K}, boldsymbol{L}, boldsymbol{M} ) and ( boldsymbol{N} ) shells of its atom? A .2,8,6,4 в. 2,8,7,3 c. 3,7,7,3 D. 2,8,8, |
11 |
| 1549 | Which of the following is true? A. The electron density in the xy-plane in 3d ( _{x y} ) orbital si zero B. The electron densities in the xy and xz-plane in 3d ( _{y z} ) orbital are zero C. The electron density in the xy-plane in ( 3 d_{x}^{2} ) orbital is zero D. Pauli exclusion principle is followed by bosons which have integral spin |
11 |
| 1550 | The phenomenon of radioactivity is associated with: A. decay of nucleus B. fussion of nucleus c. emission of electrons or protons D. rearrangement in the extra nuclear electron |
11 |
| 1551 | Assertion ( gamma- ) rays have very high penetrating power. Reason ( gamma- ) rays are electromagnetic radiations of high energy. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
11 |
| 1552 | Describe balance of oxygen in the air. | 11 |
| 1553 | The time in which activity of an element reduces to ( 90 % ) of its original value is: The half-life period of element is ( 1.4 times ) ( 10^{10} ) years. A ( cdot 2.128 times 10^{9} ) years B . ( 1.578 times 10^{7} ) years c. ( 6.954 times 10^{7} ) years D. none of these |
11 |
| 1554 | Which of the following reactions led to the discovery of neutrons? A ( cdot_{6} C^{14}+_{1} p^{1} rightarrow_{7} N^{14}+_{0} n^{1} ) B. ( _{4} B e^{9}+_{2} H e^{4} rightarrow_{6} C^{12}+_{0} n^{1} ) ( mathbf{c} cdot_{5} B^{11}+_{1} D^{2} rightarrow_{6} C^{11}+_{0} n^{1} ) D. ( _{4} B e^{8}+_{2} H e^{4} rightarrow_{6} C^{11}+_{0} n^{1} ) |
11 |
| 1555 | How many nodal planes are present in ( 4 d_{z^{2}} ? ) ( A cdot 2 ) B. c. zero D. 3 |
11 |
| 1556 | Which of the following transitions will involve maximum amount of energy? A ( . M rightarrow M^{+}+e^{-} ) B. ( M^{-} rightarrow M^{+}+2 e^{-} ) ( mathbf{c} cdot M^{2+} rightarrow M^{3+}+e^{-} ) D. ( M^{+} rightarrow M^{2+}+e^{-} ) |
11 |
| 1557 | The absolute value of charge on the electron was determined by: A. J.J. Thomson B. R.A. Millikan c. Rutherford D. chadwick |
11 |
| 1558 | A body of mass 10 mg is moving with a velocity of ( 100 m s^{-1} . ) The wavelength of the de Broglie wave associated with it would be A ( cdot 6.63 times 10^{-7} mathrm{m} ) B. ( 6.63 times 10^{-31} m ) ( c cdot 6.63 times 10^{-4} m ) D. ( 6.63 times 10^{-35} m ) |
11 |
| 1559 | From Bohr’s model, radius of the orbit and energy of the hydrogen atom are calculated as: This question has multiple correct options A. the radius of the ( 1^{s t} ) orbit is ( 0.529 A^{circ} ) B. the energy of the ( 1^{s t} ) orbit is ( -13.6 e V ) C. the energy of the ( 1^{s t} ) orbit is ( -21.72 times 10^{-19} J ) D. the radius of the ( 1^{s t} ) orbit is ( 1.06 A^{circ} ) |
11 |
| 1560 | Arrange the following orbitals in the order in which they are filled with electrons. ( 6 s, 5 d, 6 p, 7 s, 5 f ) A. ( 6 s<5 d<6 p<7 s<5 f ) B. ( 6 s<6 d<5 d<5 f<7 s ) c. ( 6 d<5 f<6 s<6 p<7 s ) D. ( 6 s<7 s<5 d<5 f<6 p ) |
11 |
| 1561 | The emission of beta particles is from: A. the valence shell of an atom B. the inner shell of an atom C. the nucleus due to the nuclear conversion proton ( rightarrow ) neutron + electron D. the nucleus due to the nuclear conversion neutron ( rightarrow ) proton + electron |
11 |
| 1562 | The energy of an electron in the first Bohr orbit of H atom is -13.6 eV. The possible energy value of the excited state for the electron in Bohr orbits of hydrogen is: A. -3.4 eV B. 4.2 eV ( mathbf{c} .-6.8 mathrm{eV} ) D. ( +6.8 mathrm{eV} ) |
11 |
| 1563 | Which element has a mass number of 20 and contains 11 neutrons?? A. copper B. Gallium c. calcium D. Sodium E. Fluorine |
11 |
| 1564 | Following results are observed when sodium metal is irradiated with different wavelengths. Calculate (a) threshold wavelength and (b) Plancks constant. 500 [ lambda(n m) ] 450 ( v times 10^{-5}left(mathrm{cms}^{-1}right) ) 2.55 4.35 |
11 |
| 1565 | Which of these are the characteristics of wave function ( mathbf{Psi} ? ) This question has multiple correct options A. ( Psi ) must be single valued в. ( int_{-infty}^{+infty} Psi^{2} d x d y d z=1 ) c. ( Psi ) must be finite and continous D. ( Psi ) represents a standing wave |
11 |
| 1566 | Which of the following are iso-electronic species? A. ( C O_{2}, N O_{2} ) B. ( N O_{2}^{-}, C O_{2} ) c. ( C N^{-}, C O ) D. ( S O_{2}, C O_{2} ) |
11 |
| 1567 | The number of radial nodes for ( 4 p ) orbital is: A . 4 B. 3 ( c cdot 2 ) D. |
11 |
| 1568 | Which of the following sets of quantum numbers represents the 19th electron of ( boldsymbol{C r}(boldsymbol{Z}=mathbf{2 4}) ? ) ( ^{mathbf{A}} cdotleft(4,1,-1,+frac{1}{2}right) ) в. ( left(4,0,0,+frac{1}{2}right) ) c. ( left(3,2,0,-frac{1}{2}right) ) D. ( left(3,2,-2,+frac{1}{2}right) ) |
11 |
| 1569 | What will be the uncertainty in velocity of a bullet with a mass of ( 10 g ) whose position is known with ( pm 0.01 mathrm{mm} ) ? |
11 |
| 1570 | Concept of stationary orbit was introduced by : A. Bohr B. Rutherford c. Sommerfeld D. Thomson |
11 |
| 1571 | The energy required to break one mole of hydrogen-hydrogen bonds in ( H_{2} ) is ( 436 k J . ) What is the longest wavelength of light required to break a single hydrogen-hydrogen bond? A ( .68 .5 mathrm{nm} ) в. 137 пт ( c .274 n m ) D. 548 пт |
11 |
| 1572 | The number of unpaired electrons in a chromic ion ( left.C r^{+3} text {(atomic number } 24right) ) is: ( A cdot 6 ) B. 4 ( c cdot 3 ) D. |
11 |
| 1573 | The ratio of the difference in energy between the first and second Bohr orbit to that between second and third Bohr in H-atom is: ( A cdot 4 / 9 ) B. ( 1 / 3 ) c. ( 27 / 5 ) D. ( 1 / 2 ) |
11 |
| 1574 | Total number of nodes present in ( 4 d^{-} ) orbitals will be ( mathbf{A} cdot mathbf{3} ) B . 2 c. 1 D. 0 |
11 |
| 1575 | Explanation of the presence of three unpaired electrons in nitrogen atom is given by: A. Pauli’s principle B. Hund’s rule c. Aufbau principle D. Uncertainty principle |
11 |
| 1576 | Quantum number ( (n=3) ) has: A. s, p electrons B. s, p, d, electrons c. s electrons D. s,p,d,f electrons |
11 |
| 1577 | Assertion The mass spectrometer is used for determination of the atomic mass of isotopes. Reason Isotopes are the atoms of the same element having a same atomic number but different mass numbers A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is incorrect but Reason is correct D. Both Assertion and Reason are incorrect |
11 |
| 1578 | What is the maximum number of emission lines when the excited electron of ( mathrm{H} ) atom in ( mathrm{n}=6 ) drops to the ground state? |
11 |
| 1579 | According to Bohr’s theory, the energy required for the transition of H-atom from ( n=6 ) to ( n=8 ) state is: A. equal to the energy required for the transition from ( n= ) 5 to ( n=6 ) state B. larger than the energy required for the transition from ( n=7 ) to ( n=9 ) state c. less than the energy required for the transition from n ( =7 ) to ( n=9 ) state D. equal to the energy required for the transition from ( n= ) 7 to ( n=9 ) state |
11 |
| 1580 | State True or False. ( 24 t h ) electron in ( C r ) enters in ( 3 d ) -orbital. A. True B. False |
11 |
| 1581 | CELLUL CICLU On calulot De uericu. Q62. The quantum numbers of six electrons are given below. Arrange them in order of increasing energies. If any of these combination (s) has/have the same energy? (i) n = 4, 1 = 2, m, = -2, m = -1/2 (ii) n = 3,1 = 2, m, = 1, m = + 1/2 (iii)n = 4,1 = 1, m, = 0, m = + 1/2 (iv) n = 3,1 = 2, m, = -2, m, = -1/2 (v) n = 3,1 = 1, m, = -1, m = +1/2 (vi) n = 4, 1 = 1, m, = 0, m = + 1/2 |
11 |
| 1582 | Assertion Half-filled and fully-filled degenerate orbitals are more stable. Reason Extra stability is due to the symmetrical distribution of electrons and exchange energy. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
11 |
| 1583 | The nuclear model of the atom was suggested by: A. Bohr B. Rutherford c. Pauli D. Mendeleef |
11 |
| 1584 | The electron density between ( 1 s ) and ( 2 s ) is: A . high B. low c. zero D. abnormal |
11 |
| 1585 | For an electron with ( n=3 ) has only one radial node. The orbital angular momentum of the electron will be : A. 0 B. ( sqrt{6} frac{h}{2 pi} ) c. ( sqrt{2} frac{h}{2 pi} ) D ( cdot 3left(frac{h}{2 pi}right) ) |
11 |
| 1586 | Assertion An orbital cannot have more than two electrons. Reason The two electrons in an orbital create opposite magnetic field. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
11 |
| 1587 | Calculate the difference in the number of carbon atoms in 1.0 g of ( C-14 ) isotope and ( 1.0 mathrm{g} ) of ( C-12 ) isotope. A ( .7 .2 times 10^{21} ) B. ( 6.2 times 10^{20} ) C ( cdot 6.2 times 10^{22} ) D. ( 7.2 times 10^{20} ) |
11 |
| 1588 | A transition of electron from an higher orbit to ( 2^{n d} ) orbit produces 10 spectral lines. The higher orbit no. is : A. seven B. eight c. six D. five |
11 |
| 1589 | Energy associated with an orbit as its distance increases from the nucleus. A. increases B. decreases c. no relation D. may increase or decrease depending on distance from the nearest orbit |
11 |
| 1590 | When photons of energy ( 4.25 e V ) strike the surface of a metal ( A ), the ejected photo-electrons have maximum kinetic energy, ( boldsymbol{T}_{A}(text { expresses in } boldsymbol{e} boldsymbol{V}) ) and de Broglie wavelength ( lambda_{A} ). The maximum kinetic energy of photoelectrons liberated from another metal ( B ) by photons of energy ( 4.70 e V ) is ( T_{B}=T_{A}- ) 1.50 ( e V ). If the de-Broglie wavelength of these photo-electrons is ( lambda_{B}=2 lambda_{A}, ) then which is not correct? A. The work function of ( A ) is ( 2.25 e V ) B. The work function of ( B ) is ( 1.20 e V ) ( mathbf{c} cdot T_{A}=2.00 e V ) D. ( T_{B}=0.5 e V ) |
11 |
| 1591 | A plot of kinetic energy of the emitted electron against frequency of the incident radiation yields a straight line. The slope of the straight line is: A. ( 0.66 times 10^{-35} ) В. ( 0.66 times 10^{-33} ) c. ( 0.33 times 10^{-33} ) D. ( 3.33 times 10^{-35} ) |
11 |
| 1592 | Which of the following properties can only be a whole number? A. Atomic mass B. Atomic volume c. Atomic radius D. Mass number |
11 |
| 1593 | Not considering the electronic spin, the degeneracy of the second excited state ( (n=3) ) of ( H ) -atom is ( 9, ) while the degeneracy of the second excited state of ( boldsymbol{H}^{-} ) is |
11 |
| 1594 | What are the total number of orbitals and electrons for ( m=0, ) if there are 30 protons in an atom? A. 6 orbitals, 12 electrons B. 5 orbitals, 10 electrons c. 7 orbitals, 14 electrons D. 4 orbitals, 8 electrons |
11 |
| 1595 | If ( Z ) is the atomic number of a one- electron species and ( n ) is the orbit in which the electron is revolving, show that the number of revolutions made by the electron in that orbit in 1 second times is directly proportional to ( frac{Z^{2}}{n^{3}} ) |
11 |
| 1596 | Calculate the uncertainly is the positive of dust particle with mass equal to Img.ln uncertainly in velocity is ( 5.5 times ) ( mathbf{1 0}^{-mathbf{2 0}} boldsymbol{m} / boldsymbol{s} ) | 11 |
| 1597 | The is the smallest unit of matter. A. Element B. Atom c. Molecule D. Electron |
11 |
| 1598 | What will be the wavelength of an electron moving with ( frac{1}{10} t h ) of velocity of light? A ( cdot 2.43 times 10^{-11} mathrm{m} ) В . ( 243 times 10^{-11} ) и ( c .0 .243 m ) D. 2.43 ( times 10^{-4} mathrm{m} ) |
11 |
| 1599 | ( ln Psi_{321} ) the sum of angular momentum, spherical nodes and angular mode is: A ( cdot frac{sqrt{6 h}+4 pi}{2 pi} ) в. ( frac{sqrt{6 h}}{2 pi}+3 ) c. ( frac{sqrt{6 h}+2 pi}{2 pi} ) D. ( frac{sqrt{6 h}+8 pi}{2 pi} ) |
11 |
| 1600 | The angular momentum of an electron present in the excited state of Hydrogen is ( frac{1.5 h}{pi} . ) The electron is present in: A. third orbit B. second orbit c. fourth orbit D. fifth orbit |
11 |
| 1601 | If the threshold wavelength ( left(lambda_{0}right) ) for the ejection of an electron from metal is ( 330 mathrm{nm}, ) then work function for the photoelectric emission is: B. ( 1.2 times 10^{-20} ) 」 D. ( 6 times 10^{-12} ) J |
11 |
| 1602 | If the radius of the hydrogen atom is 53 ( mathrm{pm}, ) the radius of the ( H e^{+} ) ion is closest to: A ( .108 mathrm{pm} ) B. ( 81 mathrm{pm} ) c. 27 pm D. 13 pm |
11 |
| 1603 | Calculate the wavelength of an electron moving with a velocity of ( 2.05 times ) ( 10^{7} m s^{-1} ) |
11 |
| 1604 | Select the species which are isoelectronic. A ( cdot F^{-}, M g^{2+} ) в. ( A r, K ) c. ( M g^{2+}, O^{-} ) D. ( R b^{+}, A r ) |
11 |
| 1605 | By what factor the velocity of an electron in a Bohr’s orbit for a hydrogen atom will change, if the principal quantum number is doubled: A. velocity is doubled B. velocity is halved C . velocity is reduced to ( frac{1}{3} ) D. velocity remains unchanged |
11 |
| 1606 | The wavelength of the radiation emitted when an electron falls from Bohr orbit 4 to 2 in hydrogen atom is: A . 243 nm В. 972 пт c. 486 пт D. 182 nm |
11 |
| 1607 | Find number of protons and neutrons for ( (a),(b) ) and ( (c) ) respectively. (a) ( _{17}^{35} C l(b)_{6}^{12} C(c)_{35}^{81} B r ) ( A cdot n_{p}=17,6,35 ) ( n_{n}=18,6,46 ) B . ( n_{p}=16,6,35 ) ( n_{n}=18,6,46 ) ( c cdot n_{p}=17,6,35 ) ( n_{n}=18,6,45 ) D ( . n_{p}=16,6,35 ) ( n_{n}=18,6,45 ) |
11 |
| 1608 | The percentage of an element ( M ) is 53 percentage in its oxide of molecular formula ( M_{2} O_{3} ). Its atomic mass is about: A . 45 B. 9 ( c cdot 18 ) D. 38 E. 27 |
11 |
| 1609 | Select the correct statement. A. The charge to mass ratio of the particles in anode rays depend on the gas present in the tube B. Behavior of cathode rays particle and anode rays particle are same in presence of magnetic field (in terms of extent of deviations) C. Cathode and anode rays start from cathode and anode respectively D. The charge to mass ratio of the particle in cathode rays depends on the voltage applied across the terminal |
11 |
| 1610 | 36. Alpha particle is the nucleus of an atom of (1) Lithium (2) Hydrogen (3) Helium (4) Oxygen |
11 |
| 1611 | The work function of a metal is ( 4.2 mathrm{eV} ). If radiation of ( 2000 A^{circ} ) falls on the metal, the kinetic energy of the fastest photoelectron is: A . ( 1.6 times 10^{-19} mathrm{J} ) В. ( 16 times 10^{-10} J ) c. ( 3.2 times 10^{-19} mathrm{J} ) D. ( 6.4 times 10^{-10} mathrm{J} ) |
11 |
| 1612 | Calculate the energy associated with the first orbit of ( H e^{+} . ) What is the radius of this orbit? |
11 |
| 1613 | An isotone of ( _{32}^{76} ) Ge is : ( A cdot_{34}^{78} S e ) ( mathrm{c} cdot frac{78}{33} mathrm{Se} ) D. ( frac{77}{32} ) Ge |
11 |
| 1614 | Which of this have same chemical properties, but their physical properties may be different? A. Atomic number B. Mass number c. Isotopes D. Isobars |
11 |
| 1615 | Which of following was not explained by Rutherford? A. Arrangement of electrons around the nucleus B. Arrangement of protons c. Arrangement of nuetrons D. None of the above |
11 |
| 1616 | State True or False. The magnetic quantum number gives the orientation of electron clouds with respect to external magnetic field. A . True B. False |
11 |
| 1617 | Draw the geometrical representation of the atom of the element ( _{8}^{16} boldsymbol{O} ) | 11 |
| 1618 | What do you understand by isotopes? Given one example. | 11 |
| 1619 | Q30. From the following sets of quantum numbers, state which are possible. Explain why the others are not possible. (i) n= 0,1 = 0, m, = 0, m = + 1/2 (ii) n= 1, 1 = 0, m = 0, m = -1/2 (iii) n = 1, 1 = 1, m, = 0, m = + 1/2 (iv) n = 1,1 = 0, m, = + 1, m = + 1/2 (v) n = 3,1 = 3, m, = -3, m = + 1/2 (vi) n = 3,1 = 1, m, = 0, m = + 1/2 |
11 |
| 1620 | Give the number of neutrons in an atom of the isotope ( _{47}^{107} A g ) A . 59 B. 60 ( c .61 ) D. 58 |
11 |
| 1621 | Light of frequency ( 7.21 times 10^{14} H z ) is incident on a metal surface. Electrons with a maximum speed of ( 6.0 times ) ( 10^{5} m / s ) are ejected from the surface. What is the threshold frequency for photoemission of electrons? |
11 |
| 1622 | A ( 1-k W ) radio transmitter operates at a frequency of 880 Hz. How many photons per second does it emit? A. ( 1.71 times 10^{21} ) the ( 1.71 times 10^{1.11} ) B . ( 1.71 times 10^{30} ) c. ( 6.02 times 10^{23} ) D. ( 2.85 times 10^{26} ) |
11 |
| 1623 | Which of the following properties is different for neutral atoms of the isotopes of the same element? A. Atomic number B. Mass c. Number of electrons D. General chemical reactions |
11 |
| 1624 | The density of nucleus is of the order of: A ( cdot 10^{5} k g m^{-3} ) В. ( 10^{16} ) kgm ( ^{-3} ) ( mathbf{c} cdot 10^{17} k g m^{-3} ) D. ( 10^{25} mathrm{kgm}^{-3} ) |
11 |
| 1625 | List three rules for the linear combination of atomic orbitals. |
11 |
| 1626 | Assertion Proton, electron and neutron each has its antiparticle. Reason Antiproton and antielectron has opposite charge to proton and electron are called antiproton and positron respectively. Antineutron possess only opposite spin. A. Assertion is correct but Reason is wrong B. Assertion is wrong but Reason is correct C. Both Assertion and Reason are correct and Reason is correct explanation of Assertion D. Both Assertion and Reason are correct but Reason is not correct explanation of Assertion |
11 |
| 1627 | A d-block element has total spin value of ( +3 . ) Then, the spin only magnetic moment of the element is approximately: A. 2.83 В.M. B. 3.87 В.М. c. 5.9 в.М D. 6.93 В.М. |
11 |
| 1628 | Q11. What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions. (i) F (ii) Ar (ii) Mg** (iv) Rb bar |
11 |
| 1629 | In which of the following transformations, the ( beta ) -particles are emitted? A. Proton to neutron B. Neutron to proton c. Proton to proton D. Neutron to neutron |
11 |
| 1630 | Values of magnetic orbital quantum number for an electron of ( M ) -shell can be: ( mathbf{A} cdot 0,1,2 ) в. -2,-1,0,+1,+2 c. 0,1,2,3 D. -1,0,+1 |
11 |
| 1631 | How many ( d ) -electrons in ( C u^{+} ) (Atomic number ( =29 ) ) can have the spin quantum number ( left(-frac{1}{2}right) ? ) ( A cdot 3 ) B. 7 ( c .5 ) D. |
11 |
| 1632 | ( M g^{2+}, A l^{3+} ) have identical: A. configuration B. atoms ( c . ) ions D. molecules |
11 |
| 1633 | Calculate the energy of photon of light having frequency ( 3 times 10^{5} ) Hz. If wavelength of light is ( lambda(0.50 A A), ) then calculate its energy. |
11 |
| 1634 | Which of the following has two or more same electronic configuration? This question has multiple correct options A. Allotropes B. Amphiprotic c. Isoelectronic D. Isomers E. Isotopes |
11 |
| 1635 | Which transition emits photon of maximum frequency? A. 2 nd spectral line of Balmer series B. 2nd spectral line of Paschen series C. 5 th spectral line of Humphery series D. 1 st spectral line of Lyman series |
11 |
| 1636 | The fractional abundance of ( C l^{35} ) in a sample of chlorine containing only ( C l^{35} ) (atomic weight ( =mathbf{3 4 . 9} ) ) and ( boldsymbol{C l}^{mathbf{3 7}} ) (atomic weight ( =mathbf{3 6 . 9} ) ) isotopes, is ( mathbf{0 . 6} ) The average mass number of chlorine is A . 35.7 B. 35.8 c. 18.8 D. 35.77 |
11 |
| 1637 | Q. 12 orbita angular momentum depends on cam Q. 12 Orbital angular momentum depends on …….. (a) ? (b) n and 1 (c) n and m (d) m and s |
11 |
| 1638 | The speed of electron revolving in the 4 th orbit of a hydrogen like atom or ion is ( 1094 mathrm{km} / mathrm{s} . ) The atom or ions is: A. ( H ) в. ( H e^{+} ) ( mathrm{c} cdot L i^{2} ) ( D cdot B e^{3} ) |
11 |
| 1639 | In the pictorial representation of an orbital, the role of different intensity of shading is to find the maximum probability of an electron. A . True B. False |
11 |
| 1640 | The ratio of the difference in energy of electron between the first and second Bohr’s orbits to that between second and third Bohr’s orbits is : A. ( 1 / 3 ) в. 27/5 ( c cdot 9 / 4 ) D. ( 4 / 9 ) |
11 |
| 1641 | A metalo xide has the formula ( X_{2} O_{3} . ) It can be reduced by hydrogen to give free metal and water.0.1596 g of metal oxide requires ( 6 mathrm{mg} ) of hydrogen for complete reduction. Calculate the atomic weight of the metal(in amu). |
11 |
| 1642 | The wavelength associated with a golf ball weighing ( 200 mathrm{g} ) and moving at a speed of ( 5 m h^{-1} ) is of the order: B . ( 10^{-20} m ) ( mathbf{c} cdot 10^{-30} m ) D. ( 10^{-40} m ) |
11 |
| 1643 | Bohr modified the adding that the electrons move in orbits of fixed size and energy. A. Rutherford’s model B. Dalton’s model c. chadwick’s model D. Goldstein’s model |
11 |
| 1644 | Which of the following ion is isoelectronic with ( boldsymbol{O}^{2-} ) ? This question has multiple correct options A . ( N^{3-} ) B. ( N^{text {t }} ) ( c cdot F^{-} ) D. ( T i^{+} ) |
11 |
| 1645 | The radius of the first Bohr orbit of hydrogen atom is 0.59 , the radius of the third orbit of ( boldsymbol{H} boldsymbol{e}^{+} ) will be: ( mathbf{A} cdot 8.46 stackrel{circ}{A} ) в. 0.705 А ( mathbf{c} cdot_{1.59 A}_{A}^{circ} ) D ( cdot 2.38 stackrel{circ}{A} ) |
11 |
| 1646 | The radius of ( boldsymbol{H}- ) atom in its ground state is ( 0.53 A^{circ} . ) The radius of ( L i^{2+} ) in the similar is: ( mathbf{A} cdot 0.058 A^{circ} ) B. ( 0.171 A^{circ} ) c. ( 0.706 A^{circ} ) D. ( 1.06 A^{circ} ) |
11 |
| 1647 | The sequence of filling electrons in different shells is determined by: A. Octet rule B. Hund’s rule c. Aufbau rule D. All the above |
11 |
| 1648 | For ( n=3 ) energy level, the number of possible orbitals is: A . 1 B. 3 ( c cdot 4 ) D. |
11 |
| 1649 | Match the following Codes: [ P Q R S ] (A) 3412 ( begin{array}{llll}text { (B) } & 2 & 1 & 3 & 1end{array} ) ( (C) quad 3142 ) ( (D) quad 4123 ) (Species) (Relation) |
11 |
| 1650 | Which is the correct combination begin{tabular}{ll|l|l|} & & multicolumn{2}{l} { change } \ & & in \ Emission & Atomic number & mass number \ hline (a) & ( alpha ) & -2 & -2 \ (b) & ( beta^{-} ) & +1 & 0 \ (c) & ( gamma ) & 0 & 0 \ (d) & ( beta^{+} ) & -1 & 0 \ hline end{tabular} |
11 |
| 1651 | In a container a mixture is prepared by mixing of three samples of hydrogen, helium ion ( left(H e^{+}right) ) and lithium ion ( left(L i^{2+}right) ) In sample all the hydrogen atoms are in 1 st excited state and al the He ions are in third excited state and all the ( left(L i^{2+}right) ) ions are in fifth excited state Find the total number of spectral lines observed in the emission spectrum of such a sample, when the electrons return back upto the ground state |
11 |
| 1652 | Statement ( I:^{12} C ) is an isotope of ( ^{14} boldsymbol{C} ) Statement II :The nuclei of both atoms have the same number of neutrons. ( mathbf{A} cdot ) true, false B. false, true c. false, false D. true, true, correct explanation |
11 |
| 1653 | Assertion Atoms with completely filled and half filled subshells are stable. Reason Completely filled and half-filled subshells have the symmetrical distribution of electrons and have maximum exchange energy A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
11 |
| 1654 | Symbols ( _{35}^{79} B r ) and ( ^{79} B r ) can be written, whereas symbols ( _{79}^{35} B r ) and ( ^{35} B r ) are not acceptable. Answer briefly: | 11 |
| 1655 | Number of lobes present in ( d_{z^{2}} ) orbital is A . 10 B. 5 ( c cdot 4 ) D. 2 |
11 |
| 1656 | The dissociation energy of ( boldsymbol{H}_{2} ) is ( 482.5 K J / ) mol. If ( H_{2} ) is exposed to radiant energy of wavelength ( 124 mathrm{nm} ) what ( % ) of radiant energy will be converted into K.E? ( left(1 frac{e v}{a t o m} 5=96 k J / m o l .right) ) |
11 |
| 1657 | The ( e / m ) value for cathode rays: A. varies with the nature of the gas B. does not vary with the nature of gas C. could not be determined by J.J Thomson D. both (b) and (c) are correct |
11 |
| 1658 | According to classical theory, if an electron is moving in a circular orbit around the nucleus: A. it will continue to do so for sometime B. its orbit will continuously shrink c. its orbit will continuously enlarge D. it will continue to do so for all the time |
11 |
| 1659 | The potential energy of the electron present in the ground state of ( L i^{+2} ) ion is represented by: A ( cdot frac{+3 e^{2}}{4 pi varepsilon_{0} r} ) в. ( frac{-3 e}{4 pi varepsilon_{0} r} ) c. ( frac{-3 e^{2}}{4 pi varepsilon_{0} r} ) D. ( frac{-9 e^{2}}{4 pi varepsilon_{0} r} ) |
11 |
| 1660 | Find the radius of nucleus of an atom having atomic mass number equal to 125. ( left(text { Take } boldsymbol{R}_{0}=mathbf{1 . 3} times mathbf{1 0}^{-mathbf{1 5}} boldsymbol{m}right) ) |
11 |
| 1661 | What is the main difference between electromagnetic wave theory and Planck’s quantum theory? A. According to electromagnetic wave theory, the energy is emitted or absorbed continuously whereas according to Planck’s quantum theory, energy is emitted or absorbed discontinuously,i.e. in certain definite packets called ‘Quanta’ B. According to electromagnetic wave theory, energy is emitted or absorbed discontinuously, i.e., in certain definite packets called ‘Quanta’ whereas according to Planck’s quantum theory, the energy is emitted or absorbed continuously C. According to electromagnetic wave theory, the energy is emitted or absorbed continuously whereas according to Planck’s quantum theory, energy is emitted or absorbed continuously,i.e. in certain definite packets called ‘Quanta’ D. According to electromagnetic wave theory, the energy is emitted or absorbed discretely whereas according to Planck’s quantum theory, energy is emitted or absorbed discontinuously, i.e., in certain definite packets called’Quanta’ |
11 |
| 1662 | Match the following | 11 |
| 1663 | A neutral atom of an element has ( 2 mathrm{K}, 8 mathrm{L} ) and ( 5 mathrm{M} ) electrons. What is the total number of unpaired electrons? ( A cdot 2 ) B. 3 ( c cdot 4 ) D. 5 |
11 |
| 1664 | The frequency of ( e^{-} ) in the first Bohr orbit in a H-atom is: A. ( 6530 times 10^{12} mathrm{Hz} ) В. ( 6840 times 10^{12} mathrm{Hz} ) c. ( 6430 times 10^{12} mathrm{Hz} ) D. ( 6734 times 10^{12} mathrm{Hz} ) |
11 |
| 1665 | Number of neutrons in a parent nucleus ( X, ) which gives ( _{7}^{14} mathrm{N} ) after two successive ( beta ) -emission would be : ( A cdot 6 ) B. 7 ( c cdot 8 ) D. |
11 |
| 1666 | Rutherford’s model was not able to explain: A. Rebounding of alpha particles B. Deflection of aplha particles c. concentration of positive charge at centre D. Line spectra of Atom |
11 |
| 1667 | Angular and spherical nodes in ( 3 s ) is: A . ( 1, ) в. 1,0 ( c cdot 2,0 ) D. 0,2 |
11 |
| 1668 | The number of nodes in ( 3 p ) orbital are : | 11 |
| 1669 | What is likely to be orbit number for a circular orbit of diameter 20 nm of the hydrogen atom? A . 10 B. 14 c. 12 D. 16 |
11 |
| 1670 | Q2. What is the minimum product of uncertainty in position and momentum of an electron? Ane bo |
11 |
| 1671 | Identify the following elements. a) ( _{25} X^{55} ) b) ( _{17} X^{35} ) c) ( _{20} X^{40} ) |
11 |
| 1672 | Circumference of the first orbit of hydrogen atom is given by the formula: ( left[a_{0}=frac{h^{2}}{4 pi^{2} m e^{2}}right] ) A ( cdot frac{22}{7} a ) в. ( frac{pi a_{0}}{2} ) c. ( sqrt{4} pi a_{0} ) D. ( pi a_{0} ) |
11 |
| 1673 | State True or False. Thomson discovered isotopes. A. True B. False |
11 |
| 1674 | The following charged particles accelerated from rest, through the same potential difference, are projected towards gold nucleus in different experiments. The distance of closest approach will be maximum for A. ( alpha ) -particles B. proton c. deuteron D. neutron |
11 |
| 1675 | Which of the following is incorrect? A. Hydrogen > Deuterium > Tritium; (% relative abundance) B. Hydrogen < Deuterium < Tritium; (density/g ( L^{-1} ) ) C. Hydrogen < Deuterium < Tritium; (boiling point/K) D. Hydrogen Tritium; (melting point/K) |
11 |
| 1676 | Which of the following is an isoelectronic pair? A ( cdot K^{+}, C l^{-} ) В. ( N a^{+}, C l^{-} ) ( mathbf{c} cdot N a^{+}, H e ) D. ( H^{+}, X e ) |
11 |
| 1677 | The entire positive charge of the atom is located in the nucleus while the electrons are distributed in the vacant space around it. This statement was given by Thomson. A. True B. False |
11 |
| 1678 | State whether the given statement is true or false:
With the increase in distance from the |
11 |
| 1679 | Radiation of wavelength 242 nm is sufficient to ionize the sodium atom. Calculate the ionization energy in ( boldsymbol{k J} boldsymbol{m o l}^{-1} cdotleft(boldsymbol{n}=mathbf{6 . 6 2 5} times mathbf{1 0}^{-mathbf{3 4}} boldsymbol{J}-boldsymbol{s}right) ) A. ( 493.6 k J ) ( J ) B . ( 6.625 times 10^{3} J ) c. ( 242 k J ) D. ( 1324 k J ) |
11 |
| 1680 | An electron in the hydrogen atom is excited from ( 1^{s t} ) orbit to ( 5^{t h} ) orbit. Find the change in energy of the electron in ( e V: ) A. (13.6 ( times 24) / 25 ) B. (13.6 ( times 4) / 5 ) ( c cdot(0.529 times 4) / 5 ) D. (13.6 ( times 4) / 9 ) |
11 |
| 1681 | Which of the following statements is wrong about isotopes? A. Isotopes have same number of electrons B. Isotopes have same chemical properties C. Isotopes have same number of neutrons D. Isotopes have same number of protons |
11 |
| 1682 | The molar mass of ( N_{2} O ) as well as ( C O_{2} ) is ( 44 g m o l^{-1} . A t 25^{o} C ) and 1 atm pressure, ( 1 mathrm{L} N_{2} mathrm{O} ) contains ( mathrm{n} ) molecules of gas. The number of ( C O_{2} ) molecules in 2 L under same conditions will be: ( A ) B. ( 2 n ) ( c cdot frac{n}{2} ) ( D cdot frac{n}{n} ) |
11 |
| 1683 | State True or False. The radial wave function for the ground state of ( H ) -atom decreases exponentially towards zero as ( r ) increases. A. True B. False |
11 |
| 1684 | The de Broglie wavelength of a particle with mass ( 1 mathrm{gm} ) and velocity ( 100 mathrm{m} / mathrm{s} ) is: A ( cdot 6.63 times 10^{-33} m ) B. ( 6.63 times 10^{-34} m ) D. ( 6.635 times 10^{-35} m ) |
11 |
| 1685 | How many ‘alpha’ and’ ( beta ) ‘-particles will be emitted when ( _{90} T h^{234} ) changes into ( 84 P o^{218} ? ) | 11 |
| 1686 | The electronic configuration of valence shell of ( C u ) is: A ( cdot 3 d^{10} 4 s^{2} ) B. ( 3 d^{9} 9 s^{2} ) ( mathbf{c} cdot 3 d^{10} 4 s ) D. ( 3 d^{10} 4 s^{0} ) |
11 |
| 1687 | Which of the following can be negative? A ( cdot 4 pi r^{2} Psi^{2} ) B . ( 4 pi r^{2} Psi^{2} d r ) ( c . Psi ) D. ( Psi^{2} ) |
11 |
| 1688 | Which of the following is not a permissible arrangement of electrons in an atom? A ( cdot n=3,1=2, m=+1, s=-frac{1}{2} ) B ( cdot n=4,1=0, m=0, s=-frac{1}{2} ) ( c cdot n=5,1=3, m=0, s=+frac{1}{2} ) D. ( n=3,1=2, m=-3, s=-frac{1}{2} ) |
11 |
| 1689 | energy increases 15. An electron beam is accelerated by a potential difference V to hit a metallic target to produce X-rays. It produces continuous as well as characteristic X-rays. If min is the smallest possible wavelength of X-ray in the spectrum, the variation of log 2 min with log Vis correctly represented in (a) log imin (b) log 2 min log v (c) log Amin →log V (d) log Amin →log V ►log V (JEE Main 2017) |
11 |
| 1690 | H-atom is exposed to electromagnetic radiation of ( lambda=1025.6 A ) and excited atom gives out induced radiations. What is the minimum wavelength of these induced radiations? A. ( 102.6 mathrm{nm} ) B. ( 12.09 mathrm{nm} ) c. ( 121.6 mathrm{nm} ) D. ( 810.8 mathrm{nm} ) |
11 |
| 1691 | 3. If 5% of the energy supplied to a bulb is irradiated as visible light, how many quanta are emitted per second by a 100 W lamp? Assume wavelength of visible light as 5.6 x 10 cm. (a) 1.4 x 1019 (b) 3 x 103 (c) 1.4 x 10-19 (d) 3 x 104 |
11 |
| 1692 | The nature of anode rays depends upon: A. nature of gas filled in the discharge tube B. nature of electrode c. nature of metal D. none of these |
11 |
| 1693 | Thomson proposed that: A. an atom consists of a positively charged sphere and the electrons are embedded in it. B. the negative and positive charges are equal in magnitude. So that atoms as a whole are electrically neutral. ( c . ) both ( A ) and ( B ) D. none of the above. |
11 |
| 1694 | Which of the following is correctly matched? A. Momentum of H-atom when electrons return from ( n=2 ) to ( n=1: frac{3 R h}{4} ) B. Momentum of proton: Independent of wavelength of light c. e/m ratio of anode rays : Independent of gas in the discharge tube D. Radius of nucleus :: (Mass no.) ( ^{1 / 2} ) |
11 |
| 1695 | What is the ratio of mass for ( alpha ) and neutron particles? A .1: 16 B. 16: 1 ( c cdot 4: ) D. 1: 4 |
11 |
| 1696 | Multiple of fine structure of spectral lines is due to: A. presence of main energy levels B. presence of sub-level c. presence of electronic configuration D. is not a characteristics of the atom. |
11 |
| 1697 | ( pi^{o} ) meson is exchanged between: A. proton and neutron B. proton and proton c. neutron and neutron D. may be between two protons or two neutrons |
11 |
| 1698 | ( boldsymbol{K}^{+}, boldsymbol{A} boldsymbol{r}, boldsymbol{C l}^{-} ) are iso electronic species A. True B. False |
11 |
| 1699 | ( frac{h}{2 pi} ) is angular momentum in orbit of ( boldsymbol{H} boldsymbol{e}^{+} ) A . first B. second c. third D. infinite |
11 |
| 1700 | Mirror nuclei are those which have: A. the same number of protons B. the same number of neutrons C. the number of protons equal to number of neutrons D. the number of neutrons in one equal to the number of protons in the other |
11 |
| 1701 | The charge to mass ratio is highest for: A. proton B. electron c. neutron D. alpha |
11 |
| 1702 | The wave number of the ( H_{alpha} ) -line in Balmer series of hydrogen spectrum is : A . 5R / 36 в. зв c. ( 21 mathrm{R} / 100 ) D. 3R / 4 |
11 |
| 1703 | Which one of the following statements is correct? A. 2 s orbital is spherical with two nodal planes B. The de Broglie wavelength ( ( lambda ) ) of a particle of mass ‘m’ and velocity ‘V’ is equal to mV/h C. The principal qantum number (n) indicates the shape of the orbital D. The electronic configuration of phosphorous is given by [Ne] ( 3 s^{2} 3 p_{x}^{1} 3 p_{y}^{1} 3 p_{z}^{1} ) |
11 |
| 1704 | 040. In Rutherford experiment, generally the thin foil of heavy atoms like gold, platinum etc., have been used to be bombarded by the a-particles. If a thin foil of light atoms like aluminium etc., is used, what difference would be observed from the above results? 1-alane amount of nocito b uone |
11 |
| 1705 | According to Thomson, an atom consists of : A. embedded electrons B. positively charged uniform sphere c. positively charged nucleus D. both a and |
11 |
| 1706 | Q26. An atom of an element contains 29 electrons and 35 neutrons. Deduce (1) the number of protons and (ii) the electronic configuration of the element. Ans. No of proton |
11 |
| 1707 | According to Bohr’s theory of hydrogen atom, the product of the binding energy of the electron in ( n^{t h} ) orbit and the radius of the ( n^{t h} ) orbit : A . is proportional to ( n^{2} ) B . is inversely proportional to ( n^{3} ) c. has a constant value of ( 10.2 e V A^{0} ) D. has a constant value of ( 7.2 e V A^{0} ) |
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| 1708 | p-subshell can accommodate a maximum of how many electrons? A. 6 B. 8 ( c cdot 4 ) ( D ) |
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| 1709 | In a hydrogen atom, the electronjumps from 3 to 2 energy level, the energy released is: A ( cdot 3.03 times 10^{-19} ) Jatom ( ^{-1} ) В. ( 1.03 times 10^{-19} ) Jatom( ^{-1} ) c. ( 3.03 times 10^{-18} ) Jatom ( ^{-1} ) D. ( 6.06 times 10^{-19} ) Jatom ( ^{-1} ) |
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| 1710 | The radial part of wave function depends on the quantum numbers: This question has multiple correct options ( A ) B. ( c cdot mid, m_{1} ) D. nonly |
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| 1711 | Transformation of uranium-238 into thorium-234 is done by the process: A. gamma decay B. nuclear fusion c. alpha decay D. positron emission E. nuclear fission |
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| 1712 | As per de Broglie’s formula a macroscopic particle of mass ( 100 g ) and moving at a velocity of ( 100 mathrm{cm} s^{-1} ) will have a wavelength of : A ( cdot 6.6 times 10^{-29} mathrm{cm} ) B . ( 6.6 times 10^{-30} mathrm{cm} ) c. ( 6.6 times 10^{-31} mathrm{cm} ) D. ( 6.6 times 10^{-32} mathrm{cm} ) |
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| 1713 | According to Bohr’s theory, the angular momentum for an electron of 5th orbit is: ( mathbf{A} cdot 10 h / pi ) в. ( 5 h / 2 pi ) ( mathbf{c} cdot 25 h / pi ) D. ( 5 pi / 2 h ) |
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| 1714 | How can an element be defined as consisting of any mixture of atoms with a given atomic number? A. Determines the mass of of element in the mixture B. Determines the chemical properties of an element c. Both A and B D. None of the above |
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| 1715 | ( mathbf{Psi}^{2}=mathbf{0} ) represents: A . a node B. an orbital c. angular wave function D. wave function |
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| 1716 | What is meant by imperfect sheilding of ( e^{-} ) by the nucleus? |
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| 1717 | A man writes his biodata with carbon pencil on the plane paper having mass 150 mg. After writing his biodata, he weighs the written paper and find its mass ( 152 mathrm{mg} ). What is the number of carbon atoms present in the paper? A ( .1 .0036 times 10^{20} ) B . ( 5.02 times 10^{20} ) begin{tabular}{l} ( c .1 .0036 times 10^{23} ) \ hline end{tabular} D. ( 0.502 times 10^{20} ) |
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| 1718 | 24. In a hydrogen atom, the electron is in nth excited state It comes down to the first excited state by emitting 10 different wavelengths. The value of n is (a) 6 (b) 7 (C) 8 (d) 9 |
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| 1719 | The ionic enthalpy of hydrogen atom is ( 1.312 times 10^{6} J ) mol ( ^{-1} . ) The energy required to excite the electron in the atom from ( n_{1}=1 ) to ( n_{2}=2 ) is: A . ( 8.51 times 10^{5} mathrm{Jmol}^{-1} ) B. ( 6.56 times 10^{5} mathrm{Jmol}^{-1} ) c. ( 7.56 times 10^{5} mathrm{Jmol}^{-1} ) D. ( 9.84 times 10^{5} mathrm{Jmol}^{-1} ) |
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| 1720 | The radius of nucleus is: A. proportional to its mass number B. inversely proportional to its mass number C. proportional to the cube root of its mass number D. not related to its mass number |
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| 1721 | Isotopes are identified by: A. positive ray analysis B. Astons’ mass spectrograph C. Dempster’s mass spectrograph D. all of the above |
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| 1722 | The energy of a photon having wavelength 700 nm is: A . 1.77 ev B. 2.47 ev c. 700 ev D. 3.57 ev |
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| 1723 | A certain dye absorbs light of ( lambda=4500 ) ( A^{circ} ) and then fluoresces light of ( lambda= ) ( 5000 A^{circ} . ) Assuming that under given conditions, ( 45 % ) of the absorbed energy is re-emitted out as fluorescence, calculate the ratio of qunts emitted out to the number of quanta absorbed. |
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| 1724 | Differentiate between Orbit and Orbital. | 11 |
| 1725 | Which is not isoelectronic with the other three? A. ( C O ) B. ( N O^{+} ) ( c cdot C N^{-} ) D. ( O_{2} ) |
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| 1726 | ( mathbf{Psi}_{1 s}=left[frac{1}{sqrt{pi a_{o}^{3}}}right] e^{-r / a_{0}} ) Above relation is wave function of hydrogen atom in ground state ( (r= ) distance of electron from nucleus and ( boldsymbol{a}_{0}=mathbf{0 . 5 2 9} times mathbf{1 0}^{-8} boldsymbol{c m} ) ). For ( mathbf{1} boldsymbol{s} ) orbital of hydrogen, the maximum probability of finding an electron is at ( r= ) A. ( a_{0} / 2 ) 2 |