Determine the number of electrons that can have the magnetic quantum number ml = -1 in an atom with the principal quantum number n = 3.

• A. 4
• B. 2
• C. 6
• D. 8

Answer: (B)

Verified step by step guidance

1. Identify the possible values for the azimuthal quantum number (l) when the principal quantum number (n) is 3. The values of l range from 0 to n-1, so l can be 0, 1, or 2.
2. For each value of l, determine the possible values of the magnetic quantum number (ml). The values of ml range from -l to +l, including zero.
3. For l = 0, ml can only be 0. For l = 1, ml can be -1, 0, or +1. For l = 2, ml can be -2, -1, 0, +1, or +2.
4. Identify which values of l allow ml to be -1. Both l = 1 and l = 2 allow ml = -1.
5. Determine the number of electrons that can occupy each orbital with ml = -1. Each orbital can hold a maximum of 2 electrons, so there are 2 electrons for each ml = -1 orbital.