Question

What do you mean by variable valency ?
Give examples. ​

Answer 1

Answer:

Certain elements combine with other atoms, donating, accepting or sharing electrons in different proportions depending on the nature of the reaction. For example, iron combines with oxygen to form ferrous oxide as well as ferric oxide. This is termed variable valency.

Answer 2

The elements having more than one valency is said to be in Variable valency. Example = Iron ion