Question

How will you find the valency of chlorine, sulphur and magnesium?

Answer 1

If the number of electrons in the outermost shell of an atom of an element is less than or equal to 4, then the valency of an element is equal to the number of electrons in the outermost shell.

If it is greater than 4 then, the valance is determined by subtracting the outermost shell of electrons from 8.

The electrons in Cl, S, and Mg are 2,8,7 ; 2,8,6 ; 2,8,2

Hence the valency of Cl, S, and Mg are 1, 2, 2 respectively.