Tiêu đề 2B.ATOMIC STRUCTURE FINAL (DN & NLR) ( 83 - 103 ).pdf ✅

NISHITH Multimedia India (Pvt.) Ltd., 83 JEE MAINS - CW - VOL - I JEE ADVANCED - VOL - I ATOMIC STRUCTURE NISHITH Multimedia India (Pvt.) Ltd., LEVEL - VI SINGLE ANSWER QUESTIONS 1. -particles of 6 MeV energy is scattered back from a silver foil. Calculate the maximum volume in which the entire charge of the atom is supposed to be concentrated? [Z for silver = 47] (A) 3.6 × 10–28 m3 (B) 5.97 × 10–42 m3 (C) 6.55 × 10–71 m3 (D)48 × 10–42 m3 2. An  particle of momentum p is bombarded on the nucleus, the distance of the closest approach is r, if the momentum of  -particle is made to 6p, then the distance of the closest approach becomes (A) 4r (B) 2r (C) 16r (D) r 36 3. When a certain metal was irradiated with a light of 8.1 × 1016 Hz frequency, the photoelectron emitted had 1.5 times the kinetic energy as the photoelectrons emitted when the same metal was irradiated with light 5.8 × 1016 Hz frequency. If the same metal is irradiated with light of 3.846 nm wave length, what will be the energy of the photoelectron emitted? (A) 1.8 × 102 eV (B) 3.65 × 10–17 J (C) 2.28 × 102 eV (D) 4.37 × 10–17 J 4. Threshold frequency of a metal is 0 f . When light of frequency 0 v 2f  is incident on the metal plate, maximum velocity of e- emitted is 1 v . when frequency of incident radiation is 0 5f , maximum velocity of emitted e- is V2 . Find ratio of 1 2 v v (A) 1:4 (B) 1:2 (C) 2:1 (D) 4:1 5. A light source of wavelenght  illuminates a metal and ejects photo-electrons with (K.E.)max =1.eV Another light source of wavelenght 3  , ejects photo-electrons from same metal with (K.E.)max =4eV Find the value of work function? (A) 1 eV (B) 2 eV (C) 0.5 eV (D) 1.5 eV 6. If the energy of H-atom in the ground state is -E, the velocity of photo-electron emitted when a photo having energy Ep strikes a stationary Li2+ ion in ground state, is given by: (A) 2 E E  p  v m   (B) 2 E 9E  p  v m   (C) 2 E 9E  p  v m   (D) 2 E 3E  p  v m   7. In a photoelectric experiment, the stopping potential “V” is plotted against the frequency v of the incident light . The resulting curve is a straight line which makes an angle  with the x-axis . Then tan  will be equal to : (here  =work function of the surface) (A) h / e (B) e / h (C)  / e (D) eh / . 8. 4000 0 A photon is used to break the iodine molecule, then the % of energy converted to the K.E of iodine atoms if bond dissociation energy of I2 molecule is 246.5kJ/mol (A) 8% (B) 12% (C) 17% (D) 25% 9. 1 mole of He+ ion is excited. Spectral analy- sis showed the existence of 50% ions in 3rd level, 25% in 2nd level and remaining 25% in ground state. The total energy evolved when all the ions return to ground state is (A) 232.88 × 104 J (B) 331.13 × 104 J (C) 58.22 × 104 J (D) 660 × 104 J 10. The wave number of the first line in the Balmer series of hydrogen atom is 15200 cm–1. What is the wave number of the first line in the Balmer series of Be3+? (A) 2.432  105 cm–1 (B) 15200 cm–1 (C) 4  15200 cm–1 (D) 2  15200 cm–1 11. An electron in a Bohr orbit of hydrogen atom with the quantum no. n2 has an angular m o m e n t u m 4.2176  10–34 kg m2 s–1. If electron drops from this level to the next lower level. Find the wavelength of this line? (A)18.75  10–7 m (B)1.87  10–7 m (C)187.5  10–7 m (D)0.187  10–7 m
ATOMIC STRUCTURE 84 NISHITH Multimedia India (Pvt.) Ltd., JEE ADVANCED - VOL - I NISHITH Multimedia India (Pvt.) Ltd., 12. Select the incorrect graph for velocity of e- in an orbit vs.Z, 1 n and n: (A) V n (B) v 1/n (C) v z (D) v n 13. What is the frequency of revolution of electron present in 2nd Bohr’s orbit of H- atom? (A) 16 1 1.016 10 s  (B) 16 1 4.065 10 s  (C) 15 1 1.626 10 s  (D) 16 1 8.13 10 s  14. According to Bohr’s atomic theory, which of the following is correct? (A) Potential energy of electron 2 2 Z n  (B) The product of velocity of electron and pricniple quantum numeber (n) 2 Z (C) Frequency of revolution of electron in an orbit 2 3 Z n  (D) Coulombic force of attraction on the electron 2 2 Z n  15. Find the value of wave number (v ) in terms of Rydberg’s constant, when transition of electron takes place between two levels of He+ ion whose sum is 4 and difference is 2. (A) H 8R 9 (B) H 32R 9 (C) H 3R 4 (D) H 6R 9 16. A hydrogen atom in the ground state is excited by monochromatic radiation of wavelength  0 A , The resulting spectrum consists of maximum 15 different lines. What is the wavelenght  ?   1 109737  R cm H  (A) 937.3 0 A (B) 1025 0 A (C) 1236 0 A (D) 618 0 A 17. What is the angular velocity  of an electron occupying second orbit of Li2+ ion? (A) 3 4 2 3 8 me K h  (B) 3 4 2 3 8 me K 9h  (C) 3 4 2 3 64 8 me K 9 9h   (D) 3 4 2 3 9 me K h  18. The angular momentum of an electron in a Bohr’s orbit of He+ is 34 2 3.1652 10 kg m / sec    . What is the wave number in terms of Rydberg constant (R) of the spectral line emitted when an electron falls from this level to the first excited state. 34 Use h 6.626 10       (A) 3RH (B) 5 9 RH (C) 3 9 RH (D) 8 9 RH 19. When an elecron makes a transition from (n+1) state to nth state, the frequency of emitted radistions is related to n according to (n>>1): (A) 2 3 2CZ RH n   (B) 2 4 CZ RH n   (C) 2 2 CZ RH n   (D) 2 2 2CZ RH n   20. Monochromatic radiation of specific wavelength is incident on H-atoms in ground state. H-atoms absorb energy and emit subsequently radiations of six different wavelength. Find wavelength of incident radiations: (A) 9.75 nm (B) 50 nm (C) 85.8 nm (D) 97.25 nm
NISHITH Multimedia India (Pvt.) Ltd., 85 JEE MAINS - CW - VOL - I JEE ADVANCED - VOL - I ATOMIC STRUCTURE NISHITH Multimedia India (Pvt.) Ltd., 21. for a hypothetical H like atom which follows Bohr’s model, some spectral lines were observed as shown . If it is known that line’E’ belongs to the visible region, then the lines possibly belonging to ultraviolet region will be(n1 is not necessarily ground state). [Assume for this atom, no spectral series shows overlaps with other series in the emission spectrum A C B D E n5 n4 n3 n2 n1 (A) B and D (B) D only (C) C only (D) A only 22. When an electron makes a transition from (n+1) state to n state, the frequency of emitted radiation s is related to n according to (n>>1) (A) 3 v n   (B) 2 v n  (C) 3 v n  (D) 2/3 v n  23. Light from a discharge tube containing H- atoms in some excited state, falls on the metallic surface of metal Na. The KE of the fastest photo-electron was found to be 10.93eV. If He+ ions were present in the same excited state, the KE of the fastest photo- electron would have been 49.18 eV. Determine the excited state orbit number and work function of Na. (A) 2,18.2 ev (B) 4,1.82 ev (C) 3,16 ev (D) 2,1.6 ev 24. Be3+ and a proton are accelerated by the same potential, their de-Broglie wavelenghts have the ratio (assume mass of proto=mass of neutron): (A) 1:2 (B) 1:4 (C) 1:1 (D) 1:3 3 25. The mass of an electron is m, charge is e and it is accelerated from rest through a potential difference of V volts. The velocity acquired by electron will be: (A) V m (B) eV m (C) 2eV m (D) zero 26. An electron is continuously accelerated in a vacuum tube by applying potential difference. If the de-Broglie’s wavelength is decreased by 10%, the change in the kinetic energy of the electron is nearly (A) decreased by 11% (B) increased by 23.4% (C) increased by 10% (D) increased by 11.1% 27. An electron of mass m, when accelerated through a potential difference V, has de Broglie wavelength  . The de Broglie wavelength associated with a proton of mass M, accelerated through the same potentail difference will be (A) M m  (B) m M  (C) M m  (D) m M  28. If uncertainty in momentum is twice the uncertainty in position of an electron then uncertainty in velocity is: h h 2         (A) 1 h 2m (B) h 4 m (C) 1 h 4m (D) 1 h m 29. For a 3s-orbital     3 2 2 2 0 1 1 3s 6 6 e ; 9 3 a             Where 0 2r.Z 3a   What is the maximum radial distance of node from nucleus? (A)   0 3 3 a Z  (B) 0 a Z (C)   0 3 3 3 a 2 Z  (D) 0 2a Z
ATOMIC STRUCTURE 86 NISHITH Multimedia India (Pvt.) Ltd., JEE ADVANCED - VOL - I NISHITH Multimedia India (Pvt.) Ltd., 30. Energy required to ionise 2 mole of gaseous He ion present in its ground state is A) 54.4 eV B) 108.8 N eV A C) 54.4 N eV A D) 108.8 eV 31. Condider the following plots for 2s-orbital : (1) (2) (3) x,y and z are respectively. (A) 2 2 2 R,R and 4 r R  (B) 2 2 2 R ,R and 4 r R  (C) 2 2 2 4 r R and R , R  (D) 2 2 2 R , 4 r R and R  32. If n and l are principal and azimuthal quantum numbers respectively, then the expression for calculating the toal number of electrons in any energy level is: (A)   l n l 0 2 2 1      (B)   l n l 1 2 2 1      (C)   n 0 2 1        (D)   1 0 2 2 1 l n l l      33. Consider the following six electronic configurations (remaining inner obritals are completely filled) and mark the correct option. I. 3s 3p II. 3s 3p III. IV. 4s 3d V. VI. 4s 3d (A) Stability order: II > I > IV > III (B) Order of spin multiplicity: IV > III = I > II (C) V does not violate all the three rules of electronic configuration (D) If VI represents A and A+ when kept near a magnet, acts as diamagnetic substance. 34. The above electronic configuration deviates from (I) Hund’s rule (II) Aufbau principle (III) Pauli’s rule (A) All of the above (B) Only I, II (C) Only I, III (D) Only II, III 35. The ratio of magnetic moments of Fe(III) and Co(II) is: (A) 5 : 7 (B) 35 : 15 (C) 7: 3 (D) 24 : 15