Question

The electrons identified by quantum numbers n and :

can be placed in order of increasing energy as :

• A. n = 4, = 1
• B. n = 4, = 0
• C. n = 3, = 2
• D. n = 3, = 1

Answer 1

Answer: (B)

n = 4, = 0

Answer 2

(1) 4 p (2) 4 s (3) 3 d (4) 3 p

Acc. to (n + $\mathcal{l}$) rule, increasing order of energy (4) < (2) < (3) < (1)