Atomic Structure Level 2

ATOMIC STRUCTURE Q.1 The wave charac ter of electron experimentally verified by (A) de - Broglie (B) A. Einstein (C) Germer (D) Schrodinger Q.2 Cathode rays are (A) Electromagnetic waves (B) Radiations (C) Stream of -particles (D) Stream of electrons Q.3 was The e/m ratio for cathode rays (A) Is constant (B) Varies as the atomic number of the element forming cat hode in the di scharge tu be changes (C) Varies as atomic number of the gas in the discharge tube varies (D) Has the smallest value when the discharge tube is filled with hydrogen Q.4 Arrange the orbitals of H-atom in the increasing order of their energy 3px, 2s, 4dxy , 3s, 4pz , 3py , 4s (A) 2s < 3s = 3px = 3py < 4s = 4pz = 4dxy (B) 2s < 3s < 3px = 3py < 4s = 4pz = 4dxy (C) 2s < 3s < 3px = 3py < 4s = 4pz = 4dxy (D) 2s < 3s < 3px = 3py < 4s < 4pz < 4dxy Q.5 Electron, Proton and Neutron were respectively discovered by (A) James Chadwick, John Dalton, J.J. Thomson (B) J.J. Thomson, Goldsteine, John Dalton (C) J.J. Thomson, William Crookes, Goldsteine (D) J.J. thomson, Goldstein , James Chadwick Q.6 If the I.P. of Li+2 is 122.4 eV. Find out 6th I.P. of carbon (A) 122.4 × 4eV (B) 122.4 × 2eV (C) 122.4 × 3eV (D) 122.4 × 5eV Q.7 If W is the atomic mass and N is the atomic number of an element, the number of (A) Electrons = W – N (B) Neutrons = W – N (C) Protons = W – N (D) Electrons = W Q.8 It is known that atoms contain protons, neutrons and electrons. If the mass of neutron is assumed to be half of its original value whereas that of electron is assumed to be twice of this original value. The atomic mass of 6C12 will be (A) Twice (B) 75% less (C) 25% less (D) One-half of its original value Q.9 The energy difference between two electronic states is 46 .12 kcal /mole. What will be the frequency of the light emitted when an electron drops from the higher to the lower energy state 1 (Planck' constant = 9.52 x 10-14 kcal sec mole -1) (A) 4.84 x 10 15 cycles sec -1 (B) 4.84 x 10 -5 cycles sec-1 (C) 4.84x 10-12 cycles sec-1 (D) 4.84 x 10 14 cycles sec-1 Q.10 Electromagnetic radiation with maximum wave length is (A) Ultraviolet (B) Radio wave (C) X - rays (D) Infrared Q.11 Multiple of fine structure of spectral lines is due to (A) Presence of main energy levels (B) Presence of sub- levels (C) Presence of electronic configuration (D) Is not a characteristics of the atom. Q.12 The quantum number not obtained from the Schrodinger’s wave equation is (A) n (B) l (C) m (D) s Q.13 Wave mechanical model of the atom depends upon (A) de-Broglie concept of dual nature of electron (B) Heisenberg uncertainty principle (C) Schrodinger uncertainty principle (D) All Q.14 The correct Schrodinger's wave equation for an electron with total energy E and potential energy V is given by -  2  2  2 8 2    (E  V )  0  2 dy 2 z2 mh2  2   2   2  8 m (B) 2    2 (E  V )  0 x dy 2 dz2 h (A) (C) 2 + 2 2 + 2 + y x 2 z 2 (D) None of the above. 8  2m h2 (E - V)  =0 Q.15 Which one of the statement of quantum numbers is false (A) Quantum number were proposed out of necessity in Bohr model of the atom. (B) Knowing n and l it possible to designated a subshell . (C) The principal quantum number alone can give the complete energy of an electron in any atom. (D) Azimuthal quantum number refers to the subshell to which an electron belongs and describes the motion of the electron. Q.16 Which orbital is dumb-bell shaped (A) s-Orbital (B) p-Orbital (C) d-Orbital (D) f-Orbital Q.17 Which of the following subshell can accommodate ATOMIC STRUCTURE as many as 10 electrons (A) 2d (B) 3d (C) 3dxy (D) 3dz2 Q.18 "No two electrons in an atom can have the same set of four quantum numbers. "This principle was enunciated by (A) Heisenberg (B) Pauli (C) Maxwell (D) de Broglie. Q.19 How many spherical nodes are present in a 4s orbital in hydrogen atom (A) 0 (B) 1 (C) 2 (D) 3 Q.20 Minimum core charge is shown by the atom (A) O (B) Na (C) N (D) Mg Q.21 I.P. of hydrogen atom is equal to 13.6 eV. What is the energy required for the process : He+ + energy — He+2 + e– (A) 2 × 13.6 eV (B) 1 × 13.6 eV (C) 4 × 13.6 eV (D) None of these Q.22 If elements with principal quantum number n > 4 is not allowed in nature, the number of possible elements would be (A) 60 (B) 32 (C) 64 (D) 50 Q.23 If the values of (n +  ) is not > 3, then the maximum number of electron in all the orbital would be (A) 12 (B) 10 (C) 2 (D) 6 Q.24 It is not possible to explain the pauli's exclusion principle with the help of this atom (A) B (B) Be (C) C (D) H Q.25 Uncertainty in position and momentum are equal. Uncertainty in velocity is (A) h  (B) h 2 (C) Both (D) 1 2m h  Q.26 The nucleus of an atom is located at x = y = z = 0. If the probability of finding an s-orbital electron in a tiny volume around x = a, y = z = 0 is 1 x 10 –5, what is the probability of finding the electron in the same sized volume around x = z = 0, y = a (A) 1 x 10–5 (B) 1 x 10–5 x a –5 2 (C) 1 x 10 x a (D) 1 x 10–5 x a–1 Q.27 How fast is an electron moving if it has a wavelength equal to the distance it travels in one second (A) (C) h m h p (B) m h (D) h 2( KE) Q.28 Electron corpuscular nature is not connected with (A) Diffraction phenomenon (B) Photo electric effect (C) Compton effect (D) Mechanical effect by cathode rays Q.29 The correct statement(s) about Bohr’s orbits of hydrogen atom is/are  n 2h 2  (A) r =  2 2   4 me  (B) K.E. of the electron = –1/2 (P. E. of the electron)  h (C) Angular momentum (L) = n   2 (D) All the above Q.30 In centre-symmetrical system, the orbital angular momentum, a measure of the momentum of a particle travelling around the nucleus, is quantised. Its magnitude is h h (A) (  1) (B) (  1) 2 2 h h (C) s(s  1) (D) s(s  1) 2 2 Q.31 Each orbital has a nodal plane. Which of the following statements about nodal planes are not true (A) A plane on which there is zero probability that the electron will be found (B) A plane on which there is maximum probability that the electron will be found (C) Both (D) None Q.32 An electron, a proton and an alpha particle have kinetic energies of 16E, 4E and E respectively. What is the qualitative order of their de Broglie wavelengths (A) e > p =  (B) p = a > e (C) p < e > a (D) a < e » p Q.33 If Hund’s rule is followed, magnetic moment of Fe2+, Mn+ and Cr all having 24 electrons will be in order (A) Fe2+ < Mn+ < Cr (B) Fe2+ < Cr = Mn+ (C) Fe2+ = Mn+ < Cr (D) Mn2+ = Cr < Fe2+ Q.34 One energy difference between the states n = 2 and n = 3 is E eV, in hydrogen atom. The ionisation potential of H atom is (A) 3.2 E (B) 5. 6E (C) 7.2 E (D) 13.2 E Q.35 Magnetic moments of V(Z = 23), Cr(Z = 24), Mn(Z = 25) are x, y, z. Hence (A) x = y = z (B) x < y < z (C) x < z < y (D) z < y < x ATOMIC STRUCTURE Q.36 The speed of a proton is one hundredth of the speed of light in vacuum. What is its de-Broglie wavelength? Assume that one mole of protons has a mass equal to one gram [h = 6.626 x 10–27 erg sec] (A) 13.31 x 10–3 Å (B) 1.33 x 10–3 Å –2 (C) 13.13 x 10 Å (D) 1.31 x 10–2 Å Q.37 The ratio of E2 – E1 to E4 – E3 for the hydrogen atom is approximately equal to (A) 10 (B) 15 (C) 17 (D) 12 Q.38 Consider the following ions (1) Ni2+ (2) Co2+ (3) Cr2+ (4) Fe3+ (Atomic numbers : Cr = 24, Fe = 26, Co = 27, Ni = 28) The correct sequence of the increasing order of the number of unpaired electrons in these ions is (A) 1, 2, 3, 4 (B) 4, 2, 3, 1 (C) 1, 3, 2, 4 (D) 3, 4, 2, 1 Q.39 What are the values of the orbital angular momentum of an electron in the orbitals 1s, 3s, 3d and 2p(A) 0, 0, 6 h, (C) 0, 1, 6 , 2h (B) 1, 1, 4 , 3 (D) 0, 0, 20 , 2 6 Q.40 In an atom two electron move around the nucleus in circular orbits of radii R and 4R. The ratio of the time taken by them to complete one revolution (A) 1 : 4 (B) 4 : 1 (C) 1 : 8 (D) 8 : 7 Q.41 A beam of electrons is accelerated by a potential difference of 10000 volts. The wavelength of the wave associated with it will be (A) 0.0123 Å (B) 1.23 Å (C) 0.123 Å (D) None of these Q.42 If the number of electrons in p-orbital are two, then which one of the following is in accordance with Hund’s rule (A) p 2x p y0 p0z (B) p 0x p y2 p0z (C) p 0x p y0 p 2z (D) p x1 p y1 p0z Q.43 If there are six energy levels in H–atom then the number of lines its emission spectrum in ultra voilet region will be (A) 6 (B) 5 (C) 4 (D) 3 Q.44 Magnetic moment of X3+ ion of 3d series is 35 BM. What is atomic number of X3+ ? (A) 25 (B) 26 (C) 27 (D) 28 Q.45 An electron is moving with the velocity equal to 10% of the velocity of light. Its de-Broglie wave length will be (A) 2.4 × 10-12cm (B) 2.4 × 10-18cm (C) 2.4 × 10–9Cm (D) None of these Q.46 Correct set of four quantum numbers for the valence (outer most) electron of rubidium (Z = 37) is 1 1 (A) 5,0,0, + (B) 5,1,0, + 2 2 1 3 (C) 5,1,1, + (D) 5,0,0, – 2 2 Q.47 Ratio of time period of electron in first and second orbit of H-atom would be (A) 1 : 18 (B) 1 : 8 (C) 1 : 2 (D) 2 : 1 Q.48 If x is the velocity of an electron in first Bohr’s orbit. What would be the velocity of the electron in third Bhor’s orbit x x (A) (B) (C) 3x (D) 9 x 9 3 Q.49 The following graph between 2 probability density and distance from the nucleus represents - 2 (A) 2s (B) 3s r (C) 1s (D) 2p Q.50 The wave length of the last line of Paschen series would be (A) 9540 Å (B) 8204 Å (C) 3650 Å (D) 912 Å Q.51 The wavelength of X-ray is 10 -6 cm. Its frequency in Giga Hertz (GHz) will be (Hint : 1 Giga = 109) (A) 3 × 107 (B) 3 × 109 (C) 3 × 1010 (D) 3 × 108 Q.52 Which electronic level would allow the hydrogen atom to absorb a photon but not to emit a photon (A) 3s (B) 2p (C) 2s (D) 1s Q.53 Pauli’s exclusion principle states that (A) Nucleus of an atom contains no nagative charge (B) Electrons move in circular orbits around the nucleus (C) Electrons occupy orbitals of lowest energy (D) All the four quantum numbers of two electrons in an atom cannot be equal. ATOMIC STRUCTURE Q.54 Which element is represented by the following electronic configuration - (A) Nitrogen (C) Fluorine (B) Oxygen (D) Neon Q.55 When an electron jumps from L to K shell (A) Energy is absorbed (B) Energy is released (C) Energy is neither absorbed nor released (D) Energy is sometimes absorbed and some times released Q.56 The orbital diagram in which ‘Aufbau principle’ is violated is 2s 2p (A) radiations which can not be deflected by electrical or magnetic field are given out. These are (A) A beam of protons (B) Alpha rays (C) A beam of neutrons (D) A beam of neutrons and protons Q.62 The potential energies of first, second and third Bohr’s orbits of He + cation are E1, E2 and E3. The correct sequence of these energies is (A) E1 > E2 > E3 (B) E1 = E2 > E3 (C) E1 = E2 = E3 (D) E3 > E2 > E1 Q.63 Which of the following is correct radial probability distribution curve for various orbitals ? 3s (A) 24 r2 (B) r 4p (C) (D) (B) 24 r2 Q.57 d6 configuration will result in total spin of (A) 3/2 (B) 1/2 (C) 2 (D) 1 Q.58 Bohr’s model can explain (A) The spectrum of only hydrogen atom (B) The spectrum of the atoms of all the elements (C) The spectrum of only sodium atom (D) The spectrum of atomic or ionic species having one electron. r 1s (C) r 3p Q.59 The mass number of dispositive Zn ion is 70. The total number of neutrons is (A) 34 (B) 40 (C) 36 (D) 38 Q.60 The energy required to separate an electron from the level n = 3 of an atom is 9.69 × 10-19 Joules. What will be its energy in first excited state (A) – 9 × 9.69 × 10–19J (B) – 9  9.69  10 4 19 J 4 × 9.69 × 10–19 J 9 (D) None of these (C) Q.61 When beryllium is bombarded with alpha particles (Chadwick’s experiment) extremely penetrating 24 r2 24 r2 (D) r Q.64 In which of the following orbital diagrams are both Pauli's exclusion principle and Hund's rule violated ? (A) (B) ATOMIC STRUCTURE (C) Q.73 The number of electrons in Na, having n+ = 3 (A) 4 (B) 6 (C) 7 (D) 8 (D) Q.74 Which orbital has 1 nodal plane (A) s (B) p (C) d (D) f Q.65 What are the values of the orbital angular momentum of an electron in the orbitals 1s, 3s, 3d, and 2p ? (A) 0, 0, 6, 2 (B) 1, 1, 4, 2 (C) 0, 1 6, 3 (D) 0, 0, 20  , 6  Q.66 Which of the following graphs correspond to one node ? (A)   (B) a0 Q.79 The total energy associated per quanta with light of wavelength 600 nm (A) 3.3 × 10–12 erg (B) 3.3 × 10–6 erg (C) 6.6 × 10–12 erg (D) 6.6 × 10–6 erg  (C) (D) a0 Q.77 The correct set of quantum numbers to the unpaired electron of fluorine atom (A) n = 3,  = 0, m = 0 (B) n = 3,  = 1, m = 1 (C) n = 2,  = 0, m = 0 (D) n = 2,  = 1, m = 1 Q.78 Which of the following statement is correct (A) Number of angular nodes = n – – 1 (B) Number of radial nodes =  (C) Total number of nodes = n – 1 (D) All a0  Q.75 How many s electron are there in Cu+ (A) 2 (B) 4 (C) 6 (D) 10 Q.76 If the total energy of an electron in a hydrogen atom in excited state is –3.4 eV, then the de Broglie wavelength of the electron is (A) 3.3 × 10–10 cm (B) 6.6 × 10–10 cm 10 (C) 3.3 × 10 cm (D) 9.3 × 10–12 cm a0 Q.67 The number of elliptical orbits excluding circular orbits in the N-shell of an atom is (A) 3 (B) 4 (C) 2 (D) 1 Q.68 A compound of vanadium has a magnetic moment 1.73 B. M. The electronic configuration of vanadium ion in the compound is (A) [Ar] 3d2 (B) [Ar] 3d1 (C) [Ar] 3d3 (D) [Ar] 3d04s1 Q.69 How many lines in the spectrum will be observed when electrons return from 7th shell to 2nd shell ? (A) 13 (B) 14 (C) 15 (D) 16 Q.70 In Ca atom how many e– contains m = 0 (A) 12 (B) 8 (C) 10 (D) 18 Q.71 In Ne how many e– contains m = –1 (A) 4 (B) 2 (C) 0 (D) 1 Q.72 When the wavelength of incident light on metallic plate is halved, the K.E. of emitted photoelectron will be (A) halved (B) doubled (C) unchanged (D) increased more than double Q.80 Iodine molecule dissociates into atom after absorbing light of 4500 Å. The K.E. of iodine atoms if B.E. of I2 is 240 kJ mol –1 (A) 0.43 × 10–19 J (B) 0.216 × 10–19 J –16 (C) 4.3 × 10 J (D) 2.16 × 10–16 J Q.81 The number of revolution/sec. made by electron in 3rd orbit of hydrogen atom (A) 4.88 × 1014 (B) 2.44 × 1014 14 (C) 9.9 × 10 (D) 2.44 × 1012 Q.82 Angular and spherical nodes in 3s (A) 1, 1 (B) 1, 0 (C) 2, 0 (D) 0, 2 Q.83 The magnetic moment of V4+ ion (A) 1.73 (B) 1.41 (C) 3.46 (D) 2 Q.84 Which orbital represents the following set of quantum numbers n = 3,  = 0, m = 0, s = +1/2 (A) 3p (B) 2s (C) 3s (D) 2p Q.85 The number of unpaired electrons in Zn+2 (A) 0 (B) 1 (C) 2 (D) 3 Q.86 The uncertainly in velocity of electron having uncertainty in its position of 1Å (A) 5.8 × 105 m/s (B) 5.8 × 106 m/s 7 (C) 5.8 × 10 m/s (D) 5.8 × 108 m/s ATOMIC STRUCTURE Q.87 If ionisation energy of hydrogen atom is 13.6 eV. I.E. of Li+2 will be (A) 13.6 eV (B) 10.4 eV (C) 40.8 eV (D) 122.4 eV Q.88 The wavelength of third lyman series of hydrogen atom is approximately (A) 1 × 10–7 m (B) 1 × 10–8 m –6 (C) 1 × 10 m (D) 1 × 10–5 m Q.89 The number of waves made by a Bohr electron in one complete revolution in its 3rd orbit (A) 1 (B) 2 (C) 3 (D) 4 Q.90 If potential energy of an electron in hydrogen atom is –x eV, then its kinetic energy will be (A) x eV (B) –x eV (C) 2x eV (D) x/2 eV Q.91 The number of orbitals in n = 3 are (A) 1 (B) 3 (C) 5 (D) 9 LEVEL # 2 Q.No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Ans. C D A A D A B C D B B D D C C Q.No. 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Ans. B B B D B C A A D D A A A D A Q.No. 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 Ans. B A B C C B B A A C C D B B C Q.No. 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Ans. A B B A B A D D C B B C D B B Q.No. 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 Ans. C D A D A B A B C A C D C B C Q.No. 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 Ans. B D C A B B D A C A A D A C D Q.No. 91 Ans. D