Unit 5: Atomic Structure

51. What is the main difference between the Rutherford and Bohr models of the atom?

a) Rutherford’s model included quantized orbits, Bohr’s did not
b) Bohr’s model included quantized orbits, Rutherford’s did not
c) Bohr’s model focused on neutrons, Rutherford’s on electrons
d) Rutherford’s model was based on quantum mechanics, Bohr’s was not
Answer: b) Bohr’s model included quantized orbits, Rutherford’s did not

52. Which quantum number describes the orientation of an orbital?

a) Principal quantum number
b) Azimuthal quantum number
c) Magnetic quantum number
d) Spin quantum number
Answer: c) Magnetic quantum number

53. What is the electron configuration of carbon in its ground state?

a) 1s² 2s² 2p²
b) 1s² 2s² 2p³
c) 1s² 2s¹ 2p³
d) 1s² 2s² 2p⁴
Answer: a) 1s² 2s² 2p²

54. What is the term for an atom with the same number of protons but different numbers of electrons?

a) Isotope
b) Ion
c) Isobar
d) Isomer
Answer: b) Ion

55. Which subshell follows the 4p subshell in terms of increasing energy?

a) 3d
b) 4d
c) 5s
d) 4f
Answer: c) 5s

56. Which of the following describes the Heisenberg Uncertainty Principle?

a) The exact position of an electron can always be known
b) The exact momentum of an electron can always be known
c) The exact position and momentum of an electron cannot be known simultaneously
d) Electrons have fixed paths around the nucleus
Answer: c) The exact position and momentum of an electron cannot be known simultaneously

57. Which of the following is a postulate of Dalton’s atomic theory?

a) Atoms are divisible into protons, neutrons, and electrons
b) Atoms of the same element are identical in mass and properties
c) Atoms have quantized energy levels
d) Atoms can be converted into energy
Answer: b) Atoms of the same element are identical in mass and properties

58. What is the maximum number of electrons that can occupy a single orbital?

a) 1
b) 2
c) 4
d) 6
Answer: b) 2

59. Which particle has the least mass in an atom?

a) Proton
b) Neutron
c) Electron
d) Positron
Answer: c) Electron

60. Which concept is not part of the Bohr model of the atom?

a) Electrons occupy specific orbits
b) Energy is emitted when electrons move to a lower orbit
c) Electron position is described by probabilities
d) Energy levels are quantized
Answer: c) Electron position is described by probabilities