1.2 Valency

Valency:

Valency is the combining capacity of an element with other elements. In electronic concept, valency is the number of electrons gained or lost or shared by an atom of an element during chemical reaction. Valency of an element depends on the number of valence electrons present in an element.

Variable Valency:

Some elements can show two or more than two different valencies while forming different compounds. These different valencies are due to the participation of different number of electrons while forming compounds. Such different valencies are called variable valencies.