Question

variable valency????????????​

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 .

Answer 2

Explanation:

Sometimes, because of different conditions under which a chemical reaction takes place, the valency of the same element changes. Thus metals like lead, tin, copper, mercury, iron etc exhibit variable valency.