Question

What is valancy ? How the valancy of an element is calculated

Answer 1

The valency of an atom is equal to the number of electrons in the outer shell if that number is four or less. Otherwise, the valency is equal to eight minus the number of electrons in the outer shell. Once you know the number of electrons, you can easily calculatethe valency.

Answer 2

The valency of an atom is equal to the number of electrons in the outer shell if that number is four or less. Otherwise, the valency is equal to eight minus the number of electrons in the outer shell.

Example ;

Valency of Oxygen:

The E.C of 0 is 2,6.
As 6 is lesser than 4 then It's valency is 2...