Quantum Numbers Quiz
Questions: 16 · 10 minutes
1. An electron has n = 4 and l = 1. In which subshell is it located?
3d
4p
4d
5p
2. Two electrons are in different orbitals of the same 3p subshell. Which description is consistent with that situation?
They have different n values but the same l value
They have the same values for all four quantum numbers
They must have different l values and identical m_l values
They share n = 3 and l = 1 but have different m_l values
3. How many distinct orbitals are in an f subshell?
7
5
3
14
4. Which set of quantum numbers could describe an electron in a 3d subshell?
n = 3, l = 3, m_l = 0, m_s = +1/2
n = 3, l = 1, m_l = 2, m_s = −1/2
n = 3, l = 2, m_l = −2, m_s = +1/2
n = 2, l = 2, m_l = 1, m_s = −1/2
5. What is the maximum number of electrons that can occupy one orbital?
Two with opposite spin projections
Four, representing every combination of orbital and spin direction
Two with the same spin projection
One, because each orbital has one m_l value
6. What are the allowed magnetic quantum numbers, m_l, for a d subshell?
0, 1, 2
−2, −1, 0, 1, 2
−1, 0, 1
−3, −2, −1, 0, 1, 2, 3
7. Which set lists all allowed values of the principal quantum number, n?
Positive integers: 1, 2, 3, and so on
Nonnegative integers: 0, 1, 2, 3, and so on
All integers, including negative values
Half-integers such as 1/2, 3/2, and 5/2
8. Which proposed set of quantum numbers is invalid because l is not allowed for the stated value of n?
n = 4, l = 1, m_l = 1, m_s = +1/2
n = 3, l = 2, m_l = −1, m_s = −1/2
n = 2, l = 2, m_l = 0, m_s = +1/2
n = 1, l = 0, m_l = 0, m_s = −1/2
9. For an electron with n = 3, which list contains every allowed value of the angular momentum quantum number, l?
0, 1, 2
1, 2, 3
−2, −1, 0, 1, 2
0, 1, 2, 3
10. Using the quantum-number rules, what is the maximum number of electrons in the shell with n = 3?
6
18
9
32
11. An electron is described by n = 4, l = 0, m_l = 0, and m_s = −1/2. What does this identify?
A 4p electron with negative spin projection
A 4s electron with no spin projection
A 3d electron with positive spin projection
A 4s electron with negative spin projection
12. Which statement best expresses the Pauli exclusion principle in terms of quantum numbers?
Every electron in one shell must have a different value of n
No two electrons in one atom can have the same set of all four quantum numbers
Electrons in the same subshell must all have the same spin quantum number
An orbital can contain electrons only when m_l equals zero
13. Two electrons are in the same subshell but not necessarily the same orbital. Which quantum numbers must they share?
m_l and m_s
l and m_l
n and l
n and m_s
14. Which pair gives the only allowed values of the spin quantum number, m_s, for an electron?
0 and 1
−1 and +1
−1/2 and +1/2
−1/2 and 0
15. How many different subshells are available within the shell n = 5?
4
9
25
5
16. A p subshell contains three orbitals. What is its maximum electron capacity?
2 electrons
3 electrons
4 electrons
6 electrons