# Question #ab489

Oct 17, 2016

#### Answer:

Nitrogen has variable valency because it has 5 electrons in the outermost shell and can hence attract up to 3 or lose up to 5 electrons in binding to other atoms.

#### Explanation:

Since the outer electron shell is stable with eight electrons, the presence of 5 electrons in the outermost electron shell of Nitrogen enables it to lose up to 5 or gain up to 3 electrons, giving it variable valency.

For example, in $N {H}_{3}$ it has a valency of $- 3$, but in $H N {O}_{3}$ it has a valency of $+ 5$.