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 26 of 47
- A. s-orbitals
- B. p-orbitals
- C. d-orbitals
- D. None of the given options
Explanation: The π bond is formed by the side-by-side overlap of the two unhybridized p orbitals in the two carbon atoms.
Correct answer: p-orbitals- A. Na
- B. B
- C. K
- D. Ca
Explanation: A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from the emission or absorption of…
Correct answer: Na- A. Spin quantum number
- B. Azimuthal quantum number
- C. Magnetic quantum number
- D. Principal quantum number
Explanation: Magnetic Quantum Number (m) : Gives the orientation of the orbital in space; in other words, the value of m describes whether an orbital…
Correct answer: Magnetic quantum number- A. Anode to cathode
- B. Cathode to anode
- C. Glass tube to vacuum pump
- D. Cathode through air
Explanation: Cathode rays come from the cathode because the cathode is charged negatively.
Correct answer: Cathode to anode- A. Planck quantum theory
- B. Hunds rule
- C. Pauli's exclusion principle
- D. Heisenberg's uncertainty principle
Explanation: Bohr's model of an atom is contradicted by Heisenberg's uncertainty principle.According to Bohr's model, an electron in an atom is located…
Correct answer: Heisenberg's uncertainty principle- A. 1s2
- B. 2s2
- C. 3s2
- D. 4s2
Explanation: As calcium belongs to group number IIA and period number 4, thus its electronic configuration is:Ca= [Ar] 4s²
Correct answer: 4s2- A. 1s
- B. 2p
- C. 3s
- D. 4p
Explanation: The lowest energy sublevel is always the 1s sublevel, which consists of one orbital.
Correct answer: 1s- A. 1836
- B. 1839
- C. 1837
- D. 1834
Explanation: The mass of an electron is indeed significantly smaller than the mass of a proton.
Correct answer: 1836- A. 5
- B. 6
- C. 2
- D. 3
Explanation: The orbitals are 1s, 2s, 2p, 3s, 3p, and 4s. The Calcium orbital diagram contains 2 electrons in the 1s orbital, 2 electrons in the 2s…
Correct answer: 6- A. 3
- B. 2
- C. 4
- D. 5
Explanation: Any orbital can hold a maximum of 2 electrons with opposite spin. The first shell has one 1s orbital and holds 2 electrons.
Correct answer: 2- A. s
- B. s, p
- C. s, p, d
- D. s, p, d, f
Explanation: c) s, p, dThis option is correct. The M shell includes the s, p, and d subshells.
Correct answer: s, p, d512. The atomic number of calcium is 20. The electronic structure of a calcium ion can be represented as:
- A. 2,8
- B. 2,8,4
- C. 2,8,8
- D. 2,8,8,2
Explanation: The correct electronic configuration for a calcium ion (Ca2+) is 2,8,8.
Correct answer: 2,8,8- A. [Ar]3d54s1
- B. [Ar]3d64s0
- C. [Ar]3d54s0
- D. [Ar]3d64s2
Explanation: Fe(Z=26)=[Ar]3d6As2 Fe3+ (23 electrons) = [Ar]3d5
Correct answer: [Ar]3d54s0- A. 1: 05 : 0.33
- B. 1 : 2 : 3
- C. 1 : 4 : 9
- D. 1 : 8 : 27
Explanation: The radii of the Bohr orbits are proportional to the square of the principal quantum numbers (n2).
Correct answer: 1 : 4 : 9- A. Excited state
- B. Ground state
- C. Cationic form
- D. Anionic form
Explanation: The electronic configuration 1s2, 2s2, 2p6, 3s2, 3p6, 3d5, 4s1 represents the ground state of chromium.
Correct answer: Ground state- A. E=mc2
- B. mvr=nh/2π
- C. E=hν
- D. λ=h/mv
Explanation: Planck's equation describes the relationship between the energy of a photon and its frequency.
Correct answer: E=hν- A. Maximum
- B. Zero
- C. Infinity
- D. Minimum
Explanation: This option correctly identifies the nodal plane as the region within an orbital where the electron density or probability density of…
Correct answer: Zero- A. n = 3, ℓ = 0
- B. n = 3 and ℓ = 1
- C. n = 2, ℓ = 1
- D. n = 2, ℓ = 3
Explanation: The correct option is b) n = 3, ℓ = 1. The quantum numbers describe various properties of an electron's orbital in an atom.
Correct answer: n = 3 and ℓ = 1- A. 2
- B. 3
- C. 5
- D. 7
Explanation: The correct option is c) 5. The magnetic quantum number (m) represents the orientation of an orbital within a subshell.
Correct answer: 5- A. 3-d is half filled
- B. electrons in s-orbitals
- C. 1 electron in 4s-orbital
- D. 8 electrons in s-orbitals
Explanation: Option C is true for both copper and chromium. Both copper and chromium have electrons in their s-orbitals: Cu has 1 electron in the 4s…
Correct answer: 1 electron in 4s-orbital