Question

How do you calculate the possible valency of an element from the electronic configuration of its atoms?

Answer 1

The number of electrons present in the last shell (valence electrons) determines the valency of a particular element.

There are two basic rules to calculate it:

Rule 1: If the number of valence electrons ≤ 4:

Valency = Number of valence electrons

Rule 2: If the Number of valence electrons > 4:

Valency = 8 − Number of valence electrons