Question

The number of unpaired electrons in a

nitrogen atom is 3 whereas that in an

atom of oxygen is only 2​

Answer 1

Answer:

because nitrogen is in 5th group and 8-5=3

and oxygen is in 6th group and 8-6=2

Answer 2

The explanation for the presence of three unpaired electrons in the nitrogen atom can be given by Hund's rule. According to this rule, electron pairing in any orbital (s, p, d or f) cannot take place until each orbital of the same sublevel contains 1 electron. The electronic configuration of N is 1s^2,2s^2,2p^3.

2p orbital has 3 sub-levels each of which will contain one electron. Pairing will occur only if the fourth electron is added.