Question

The maximum number of electrons in an atom in which the last electron filled has the quantum numbers n = 3, l = 2 and m = - 1 is

• A. 17
• B. 27
• C. 28
• D. 30

Answer 1

The correct option is B 27

$Co\to 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^7\therefore 3d^7$
n = 3
l = 2
m = - 1