Free Atomic Structure MCQs with Answers
922 Atomic Structure MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Atomic structure covers the discovery of the proton, Planck's quantum theory, hydrogen emission spectra and the evidence for quantized energy levels. You will use quantum numbers to describe orbitals, distinguish s, p, d and f orbital shapes, and write electronic configurations, including the correct order of electron filling.
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922 questions · page 37 of 47
- A. 1, 2
- B. 0, 1, 2
- C. 1, 2, 3
- D. -1, 0, 1
Explanation: The principal quantum number (n) determines the energy level of an electron in an atom.
Correct answer: 0, 1, 2- A. 0
- B. 1
- C. 2
- D. 3
Explanation: This option is incorrect because all orbitals, by definition, have the capacity to hold at least one electron.
Correct answer: 2- A. Principal quantum number
- B. Azimuthal quantum number
- C. Magnetic quantum number
- D. Spin quantum number
Explanation: The principal quantum number (n) represents the energy level or shell of an electron.
Correct answer: Azimuthal quantum number- A. 18
- B. 3
- C. 9
- D. 1
Explanation: This option is incorrect because, the 3p sublevel, which is one of the sublevels in n = 3, can hold a maximum of 6 electrons, and half of…
Correct answer: 9- A. 4
- B. 3
- C. 2
- D. 1
Explanation: This is incorrect. The 4s orbital has 3 spherical nodes, not 4. Applying the formula, we get: Number of spherical nodes = n - l - 1 = 4 -…
Correct answer: 3- A. 3
- B. 5
- C. 7
- D. None
Explanation: Degeneracy refers to the number of orbitals within a subshell that have the same energy.
Correct answer: 3- A. 2l+2
- B. 2(2l+1)
- C. 2l+1
- D. 2(l+1)
Explanation: The formula for calculating electrons is not 2l + 2. This option is incorrect because it adds an extra 2 to the formula.The formula…
Correct answer: 2(2l+1)- A. Different orientation and different shape
- B. Different energy and same shape
- C. Different orientation and same energy
- D. Same orientation and same shape
- E. Same energy and same orientation
Explanation: In quantum chemistry, orbitals that belong to the same subshell (such as 2p or 3d) have the same energy level but differ in their spatial…
Correct answer: Different orientation and same energy- A. 14
- B. 16
- C. 10
- D. 12
Explanation: The maximum number of electrons in a subshell is calculated using the formula 2(2l + 1), where l is the azimuthal quantum number.
Correct answer: 14- A. Magnetic quantum number
- B. Azimuthal quantum number
- C. Spin quantum number
- D. Principal quantum number
Explanation: The correct answer is the spin quantum number. This quantum number, represented as either +1/2 or -1/2, allows for the differentiation…
Correct answer: Spin quantum number- A. Electron 3 > Electron 1 > Electron 4 > Electron 2
- B. Electron 4 > Electron 2 > Electron 3 > Electron 1
- C. Electron 3 > Electron 2 > Electron 4 > Electron 1
- D. Electron 2 > Electron 4 > Electron 3 > Electron 1
Explanation: To determine the order of decreasing energy of electrons, use the (n+l) rule where 'n' is the principal quantum number and 'l' is the…
Correct answer: Electron 3 > Electron 2 > Electron 4 > Electron 1- A. Orbit
- B. Electrons in an orbit
- C. Number of orbitals
- D. Electron in an orbital
Explanation: In the context of atomic structure, an orbit generally refers to the path followed by an electron around the nucleus.
Correct answer: Number of orbitals- A. N= 2. L=0. M=0. S=+1/2
- B. N= 3. L=1. M=0. S=+1/2
- C. N= 4. L=0. M=0. S=-1/2
- D. N=3. L=0. M=0. S=+½
Explanation: The correct set of quantum numbers for the valence electron of an alkali metal in the 3rd period is N=3, L=0, M=0, S=+½, indicating a 3s…
Correct answer: N=3. L=0. M=0. S=+½- A. Electrons with same spin in same orbital
- B. Electrons with different spin in different orbital
- C. Electrons with same spin in different orbital
- D. Electrons with different spin in same orbital
- E. All are possible
Explanation: According to Pauli's exclusion principle, no two electrons in the same atom can have identical quantum numbers.
Correct answer: Electrons with same spin in same orbital- A. 2l+1
- B. 2(l+1)
- C. 2(2l+1)
- D. 2(2l-1)
Explanation: The correct formula for calculating the maximum number of electrons in a subshell is 2(2l + 1).
Correct answer: 2(2l+1)- A. Dumbbell
- B. Spherical
- C. Trigonal
- D. None of the above
Explanation: The P orbital's dumbbell shape arises from its electron density distribution, with two lobes positioned along an axis and a node at the…
Correct answer: Dumbbell- A. De-Broglie
- B. Einstein
- C. Newton
- D. Rutherford
Explanation: Louis de Broglie's wave-particle duality theory was indeed influential in understanding the behavior of particles, including electrons.
Correct answer: De-Broglie- A. λ = hv
- B. λ = hp
- C. λ = h/2λ
- D. λ = h/p
Explanation: De-Broglie's wavelength equation, λ = h/p, relates the wavelength (λ) of a particle to its momentum (p) and Planck's constant (h).
Correct answer: λ = h/p- A. 1886
- B. 1887
- C. 1895
- D. 1885
Explanation: The study of hydrogen visible spectrum occurred in 1885. During this period, scientists were actively investigating the properties of…
Correct answer: 1885- A. 1913
- B. 1919
- C. 1918
- D. 1905
Explanation: In 1913, Niels Bohr introduced his atomic model for hydrogen. He suggested that electrons move in fixed orbits around the nucleus, which…
Correct answer: 1913