For which one of the following sets of four quantum numbers, an electron will have the highest energy?n=3, l=2, m=1, s=1/2

Options

(a) n=4, l=2, m=-1, s=1/2
(b) n=4, l=1, m=0, s=-1/2
(c) n=5, l=0, m=0, s=-1/2
(d) n=4, l=2, m=-1, s=1/2

Correct Answer:

n=4, l=1, m=0, s=-1/2

Explanation:

The sub-shell are 3d, 4d, 4p and 4s, 4d has highest energy as n + l value is maximum for this.