Question

Define term valency How valency is different from valence electrons

Answer 1

valency is the combining capacity of an atom

Answer 2

The combining capacity of an atom of an element to form bonds with other elements is known as valency.
Valency is different from the number of valence electrons in case of non metals as they tend to gain electrons
Thus they contain more valence electrons and their valency is the nearest whole number to form the complete electron shell.