If the principal quantum number of an electron is n = 5, which one of the following is NOT an allowed magnetic quantum number ml for the electron?
A) 0
B) 2
C) 3
D) 4
E) 5

Question

Quizplus · Accepted Answer

The allowed values for ml range from -l to +l, where l is the azimuthal quantum number and can take integer values ranging from 0 to n-1. Therefore, for n=5, l can take integer values from 0 to 4, and ml can take integer values from -l to +l. Thus, the possible values for ml are -4, -3, -2, -1, 0, +1, +2, +3, and +4. The only value not included in this range is ml=5, so the answer is choice E.

If the Principal Quantum Number of an Electron Is N