Free Quantum Numbers MCQs with Answers
66 Quantum Numbers MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Quantum numbers describe an electron's energy level, subshell, orbital orientation and spin. You examine the principal, azimuthal, magnetic and spin quantum numbers, their allowed values, orbital capacity and how they determine electronic configurations and distinguish electrons within an atom.
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66 questions · page 3 of 4
- 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. 10
- B. 6
- C. 18
- D. 0
Explanation: In this case l = 2then m = −2,−1,0,+1,+2so there are 5 orbitals and each orbital contain 2 electronsSo for value n = 3 and l= 2 there are…
Correct answer: 10- A. Hund's rule
- B. Aufbau principle
- C. Pauli's exclusion principle
- D. All of the above options are correct
Explanation: The Pauli Exclusion Principle states that, in an atom or molecule, no two electrons can have the same four electronic quantum numbers.
Correct answer: Pauli's exclusion principle- A. Magnetic quantum number
- B. Spin quantum number
- C. Azimuthal quantum number
- D. Principle quantum number
Explanation: The Azimuthal quantum number (l) describes the shape of the orbital.
Correct answer: Azimuthal quantum number- A. n
- B. l
- C. m
- D. s
Explanation: The angular momentum quantum number determines the shape of the orbital.
Correct answer: l- A. 03
- B. 05
- C. 07
- D. 10
Explanation: Option B shows the correct value of magnetic quantum number when azimuthal quantum number is 2, the m value is: -2, -1 , 0 , +1 , +2
Correct answer: 05- A. Principal Quantum Number
- B. Spin Quantum Number
- C. Azimuthal Quantum Number
- D. Magnetic Quantum Number
Explanation: Spin quantum number is not explained through schrodinger's wave equation, whereas all other quantum number are explained according to that.
Correct answer: Spin Quantum Number- A. Less than zero
- B. more than zero
- C. one
- D. infinite
Explanation: The uncertainty principle, as described by Heisenberg, states that it is impossible to know both the exact position and momentum of a…
Correct answer: infinite- A. The energy of an electron
- B. The location of an electron
- C. The size of an orbital
- D. All of these
Explanation: The principal quantum numbers tells us about, energy level, location of electrons as well as size of orbital.
Correct answer: All of these- A. Less than zero
- B. More than zero
- C. One
- D. Infinite
Explanation: According to Heisenberg's uncertainty principle, the more precisely the momentum of an electron is known, the more uncertainty there is in…
Correct answer: Infinite- A. Principal Quantum Number
- B. Spin Quantum Number
- C. Magnetic Quantum Number
- D. Azimuthal Quantum Number
Explanation: A is incorrect as The principal quantum number, n, describes the energy of an electron and the most probable distance of the electron from…
Correct answer: Magnetic Quantum Number- A. +1, 0, -1
- B. 0, +1, +2
- C. -1, 0, +1
- D. 0, -1, +1
Explanation: The Magnetic Quantum Number (m) specifies the orientation in space of an orbital of a given energy (n) and shape (l).
Correct answer: -1, 0, +1- A. Apax-h
- B. AEA-h
- C. both (a) and (b)
- D. None
Explanation: The uncertainty principle arises from the wave-particle duality.A quite accurate measurement of one observable involves a relatively large…
Correct answer: both (a) and (b)- A. ±3
- B. ±1/2
- C. ±2
- D. Any positive number from 0 to -1
Explanation: n = 3, so possible l = 0, 1, 2For each l, m = -l to +lSo:l = 0 → m = 0l = 1 → m = -1, 0, +1l = 2 → m = -2, -1, 0, +1, +2✅ Range of m: -2…
Correct answer: ±2- A. 4
- B. 3
- C. 5
- D. 9
Explanation: This option is correct. The n=3 shell has three subshells corresponding to l=0, l=1, and l=2.
Correct answer: 3