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 20 of 47
- A. Principal quantum number (n)
- B. Angular momentum quantum number (l)
- C. Magnetic quantum number (mₗ)
- D. Spin quantum number (mₛ)
Explanation: The angular momentum quantum number (l) defines the shape of the orbital: l = 0 → s orbital → spherical, l = 1 → p orbital →…
Correct answer: Angular momentum quantum number (l)- A. 0
- B. 1
- C. 2
- D. 3
- E. 4
Explanation: The maximum number of electrons in a single orbital is two. The maximum number of electrons an orbital can accommodate is 2.
Correct answer: 2- A. 1s2, 2s2, 2p6, 3s2, 3p6, 4s2
- B. 1s2, 2s2, 2p6, 3s2, 3p6, 3s2, 3d1
- C. 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d5
- D. 1s2, 2s2, 2p6, 3s2, 3p6, 4s1
- E. 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10
Explanation: Option D is the correct option because this is the only option that has 19 electrons by adding manually.
Correct answer: 1s2, 2s2, 2p6, 3s2, 3p6, 4s1- A. Heisenberg's principle
- B. Pauli's exclusion principle
- C. Aufbau principle
- D. Hund's rule
Explanation: The heisenberg uncertainty principle states that certain pairs of physical properties, such as position and momentum, cannot be precisely…
Correct answer: Pauli's exclusion principle- A. n
- B. n2
- C. 2n2
- D. n3
- E. 3n2
Explanation: The maximum number of electrons that can be in a shell is 2n2.
Correct answer: 2n2- A. 0.529 Å
- B. 4.8 Å
- C. 2.116 Å
- D. 3.4 Å
- E. 1 Å
Explanation: In Bohr's model, the radius of the nth orbit of a hydrogen atom is given by the formula rn = 0.529 x n²/Z Å, where n is the principal…
Correct answer: 2.116 Å- A. Ionization Energy
- B. Electron Affinity
- C. Electronegativity
- D. Atomic Radius
- E. Atomisation Energy
Explanation: Electron affinity is defined as the amount of energy released when an electron is added to the valence shell of a gaseous, neutral, and…
Correct answer: Electron Affinity- A. Auf bau principle
- B. Heisenberg's principle
- C. Hund's rule
- D. Planck's statement
- E. None of these
Explanation: Hund's rule states that every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied, and…
Correct answer: Hund's rule- A. Charge of an electron
- B. Mass of an electron
- C. e/m value of an electron
- D. Charge of a proton
- E. Mass of a proton
Explanation: Thomson was able to deflect the cathode ray towards a positively charged plate deduce that the particles in the beam were negatively…
Correct answer: e/m value of an electron- A. 0.529 Å
- B. 0.529 / 4 Å
- C. 0.529 x 2 Å
- D. 0.529 x 32 Å
Explanation: Radius of the 3rd Bohr Orbit,r = 0.529n2 Å = 0.529×32 Å
Correct answer: 0.529 x 32 Å- A. Azimuthal quantum number
- B. Principal quantum number
- C. Magnetic quantum number
- D. Spin quantum number
Explanation: This is the correct answer. The azimuthal quantum number, also known as the angular momentum quantum number, determines the shape of an…
Correct answer: Azimuthal quantum number- A. n = l - 1
- B. l = n - 2
- C. l = n - 1
- D. n = l - 2
Explanation: The principal quantum number, n, describes the energy of an electron and the most probable distance of the electron from the nucleus.
Correct answer: l = n - 1- A. n=2 l=1
- B. n=1 l=2
- C. n=2 l=0
- D. n=1 l=1
Explanation: For the 2p orbital, the principal quantum number (n) is 2, indicating that the electron is in the second energy level or shell.
Correct answer: n=2 l=1- A. Li and Fe
- B. Na and Cr
- C. K and Mn
- D. H and He
Explanation: - Sodium (Na) has 11 electrons in its electron configuration [1s² 2s² 2p⁶ 3s¹]. One electron occupies the 's' orbital.
Correct answer: Na and Cr- A. A discrete series of lines of equal intensity and equally spaced with respect to wavelength equally.
- B. A series of only four lines
- C. A continuous emission of radiation of all frequencies
- D. Several discrete series of lines with both intensity and spacings between lines decreasing as the wavenumber increases with each series.
Explanation: The emission spectrum of atomic hydrogen has been divided into a number of spectral series, with wavelengths given by the Rydberg formula.
Correct answer: Several discrete series of lines with both intensity and spacings between lines decreasing as the wavenumber increases with each series.- A. Ultraviolet
- B. Visible
- C. Infrared
- D. Microwave
Explanation: The Balmer series lies in the visible region of the electromagnetic spectrum.
Correct answer: Visible- A. 1
- B. 3
- C. 5
- D. 7
- E. 9
Explanation: 2nd shell has a principal quantum number(n)=2; p-orbital has an azimuthal quantum number(l)=1; spin state=+½ implies electron spinning in…
Correct answer: 3- A. 1
- B. 0
- C. 2 x π x r
- D. >h/4π
- E. Infinite
Explanation: According to Heisenberg's uncertainty principle, it is impossible to measure position x and momentum p simultaneously.
Correct answer: Infinite- A. 30
- B. 32
- C. 42
- D. 52
Explanation: Total number of electrons in M2+ ions are 2+8+14=24, since they lost two electrons to become this ion that means neutral M will have 26…
Correct answer: 30- A. Rotation of the electron in clockwise and anticlockwise direction respectively
- B. Rotation of the electron in anticlockwise and clockwise direction respectively
- C. Magnetic movement of the electron pointing up and down respectively
- D. Two quantum mechanical spin states which have no classical analogue
Explanation: This is the most suitable option as it covers all aspects of describing the spin quantum number and its states.The two states +1/2 and…
Correct answer: Two quantum mechanical spin states which have no classical analogue