Question

For a sodium atom, the number of electrons with m = 0 will be:

• A. 2
• B. 7
• C. 9
• D. 8

Answer 1

The correct option is B 7

Electronic configuration of sodium is: $1s^{2}2s^{2}2p^{6}3s^1$
For s orbital, l = 0, m = 0
For p orbital, l = 1, m = +1, 0, -1
Hence, the number of electrons with m = 0 is:
2 (from 1s) + 2 (from 2s) + 2 (from 2p) + 1(from 3s) = 7