The electrons identified by the following quantum numbers `n` and `l: (i) n = 4, l = 1, (ii) n = 4, l = 0, (iii) n = 3, l = 2`, and (iv) `n = 3, l = 1` can be placed in the order of increasing enegry from the lowest to the highest as

Options

A. `(iv) lt (ii) lt (iii) lt (i)`
B. `(ii) lt (iv) lt (i) lt (iii)`
C. `(i) lt (iii) lt (ii) lt (iv)`
D. `(iii) lt (i) lt (iv) lt (ii)`

Answer

A

Explanation

(i) `n = 4, l = 1 rarr 4p`, (ii) `n = 4, l = 0 rarr 4s`
(iii) `n = 3, l = 2 rarr 3d`, (iv) `n = 3, l = 1 rarr 3p`
The increasing order of energy is 3p (iv) `lt 4s (ii) lt 3d (iii) lt 3p (i)`