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

Explanation

Valency of an atom is the number of electrons gained, lost or shared so as to complete the octet of electrons in the valence shell. Valency of chlorine: It has electronic configuration = 2, 8, 7 Thus, one electron is gained to complete its octet and so its valency is 1. Valency of sulphur: It has electronic configuration = 2, 8, 6 Thus, two electrons are gained to complete its octet and hence its valency = 2 Valency of magnesium : It has electronic configuration = 2, 8,2 Thus, it can lose two electrons to attain octet and hence its valency = 2