Question

Question #ab489

Answer 1

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 `NH_3` it has a valency of `-3`, but in `HNO_3` it has a valency of `+5`.