Structure of Atom NEET Questions (Solved MCQs)
Structure of Atom NEET Questions
Que 1. A packet of energy is called
(a) Electron
(b) Photon
(c) Position
(d) Proton
Ans 1. (b) Photon
Que 2. Among the following the false statement is
(a) Compared to the mass of the lightest nucleus the mass of the electron is only about 1/1836.
(b) The ratio of e/m, i.e., specific charge for a cathode ray is constant.
(c) Among He2+, H+, He+, and H the species having the highest e/m ratio is He2+.
(d) The e/m for positive rays in comparison to cathode rays is very low.
Ans 2. (c) Among He2+, H+, He+, and H the species having the highest e/m ratio is He2+.
Que 3. The number of protons, neutrons, and electrons in 71Lu175, respectively, are
(a) 71, 104 and 71
(b) 104, 71 and 71
(c) 71, 71 and 104
(d) 175, 104 and 71
Ans 3. 71Lu 175, Number of protons = Number of electrons = Atomic number = 71
Number of neutrons = Mass number – Atomic number = 175 – 71 = 104
Que 4. A neutral atom (Atomic no. > 1) consists of
(a) Only protons
(b) Neutrons + protons
(c) Neutrons + electrons
(d) Neutron + proton + electron
Ans 4. (d) Neutrons and protons in the nucleus and electrons in the extranuclear region.
Que 5. The value of Planck’s constant is 6.63 × 10 −34 Js. The speed of light is 3 × 1017 nm s –1. Which value is closest to the wavelength (in nm) of a quantum of light with a frequency of 6 × 1015 s−1?
(a) 10 nm
(b) 25 nm
(c) 50 nm
(d) 75nm
Ans 5. (c) 50 nm
Que 6. An electron beam can undergo diffraction by crystals. Through what potential a beam of electrons be accelerated so that its wavelength becomes equal to 1.54Å?
(a) 59.3 volt
(b) 69 volt
(c) 63.3 volt
(d) 72 volt
Ans 6. (c) 63.3 volt
Que 7. Orbital which is not possible
(a) 2p
(b) 3d
(c) 3s
(d) 3f
Ans 7. (d) 3f
Que 8. The wrong statement among the following is
(a) The mass of neutron is of the order 10−27 kg.
(b) Mass of neutrons is 1840 times the mass of electrons.
(c) The minimum real charge on any particle which can exist is 4.8 × 10−10 coulomb.
(d) Proton is an ionized hydrogen atom.
Ans 8. (b) Mass of neutrons is 1840 times the mass of electrons.
Que 9. Be2+ is isoelectronic with which of the following ions?
(a) H+
(b) Li+
(c) Na+
(d) Mg2+
Ans 9. (b) Li+
Que 10. Positive ions are formed from the neutral atom by the
(a) Increase of nuclear charge
(b) Gain of protons
(c) Loss of electrons
(d) Loss of protons
Ans 10. (c) Loss of electrons
Que 11. The ratio of the shortest wavelength of two spectral series of hydrogen spectrum is about 9. The spectral series are
(a) Lyman and Paschen
(b) Brackett and Pfund
(c) Paschen and Pfund
(d) Balmer and Brackett
Ans 11. (a) Lyman and Paschen
Que 12. The wavelength of a photon having an energy of 2 eV is
(a) 6.20 × 103 Å
(b) 7.10 × 104 Å
(c) 2.20 × 107 Å
(d) 4.20 × 103 Å
Ans 12. (a) 6.20 × 103 Å
(a) Size of the orbital
(b) Spin angular momentum
(c) Orbital angular momentum
(d) Orientation of the orbital in space
Ans 13. (d) Orientation of the orbital in space
Que 14. The ratio between the neutrons present in carbon and silicon with respect to atomic masses of 12 and 28 is
(a) 3:7
(b) 7:3
(c) 3:4
(d) 6:28
Ans 14. (a) 3:7
Que 15. Calculate the energy in joule corresponding to light of wavelength 45 nm. (Planck’s constant, h = 6.63 × 10–34 J s, speed of light, c = 3 × 108 m s–1)
(a) 6.67 × 1015
(b) 6.67 × 1011
(c) 4.42 × 10–15
(d) 4.42 × 10–18
Ans 15. (d) 4.42 × 10–18
Structure of Atom NEET Questions
Que 16. The magnitude of K.E. in an orbit is equal to
(a) Half of the potential energy
(b) Twice of the potential energy
(c) One-fourth of the potential energy
(d) None of these
Ans 16. (a) Half of the potential energy
Que 17. Principal, azimuthal and magnetic quantum numbers are respectively related to
(a) size, orientation, and shape
(b) size, shape, and orientation
(c) shape, size, and orientation
(d) None of the above
Ans 17. (b) size, shape, and orientation
Que 18. What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n = 4. (n = 2 of He+ Spectrum)?
(a) n1 = 2 and n2 = 4
(b) n1 = 2 and n2 = 1
(c) n1 = 1 and n2 = 2
(d) n1 = 4 and n2 = 2
Ans 18. (c) n1 = 1 and n2 = 2
Que 19. The designation of an orbital within = 4 and l = 3
(a) 4s
(b) 4p
(c) 4d
(d) 4f
Ans 19. (d) 4f
Que 20. Find out the false statement among the following.
(a) The ejection of electrons when the surface of a metal is irradiated by light is known as the Compton effect.
(b) Light, a well-known form of energy, is treated as a form of matter by saying that it consists of pho[1]tons or bundles of energy.
(c) Einstein’s theory of the photoelectric effect is based on Planck’s quantum theory.
(d) In the photoelectric effect, the photocurrent does not depend on the frequency of the photon but depends on the intensity of incident light.
Ans 20. (a) The ejection of electrons when the surface of a metal is irradiated by light is known as the Compton effect.
Que 21. What are the maximum numbers of electrons that can be associated with the following set of quantum numbers? n = 3, l = 1 and m = –1
(a) 4
(b) 2
(c) 10
(d) 6
Ans 21. (b) 2
Que 22. When an electron jumps from L to K shell
(a) Energy is absorbed
(b) Energy is released
(c) Energy is sometimes absorbed and sometimes released.
(d) Energy is neither absorbed nor released
Ans 22. (b) Energy is released
Que 23. The energy of the second Bohr orbit of the hydrogen atom is − 328 kJ mol−1; hence the energy of the fourth Bohr orbit would be …….
(a) − 41 kJmol−1
(b) − 1312 kJmol−1
(c) − 164 kJmol−1
(d) − 82 kJmol−1
Ans 23. (d) − 82 kJmol−1
Que 24. The iodine molecule dissociates into atoms after absorbing light of 4500 Å. If one quantum of radiation is absorbed by each molecule, calculate the kinetic energy of iodine atoms (Bond energy of 2 I = 240 KJ mol-1).
(a) 2.16 × 10-19 J
(b) 0.216 × 10-19 J
(c) 3.16 × 10-19 J
(d) 5.32 × 10-19 J
Ans 24. (b) 0.216 × 10-19 J
Que 25. Pauli exclusion principle helps to calculate the maximum number of electrons that can be accommodated in any
(a) Orbital
(b) Subshell
(c) Shell
(d) All of these
Ans 25. (a) Orbital
Structure of Atom NEET Questions
