valency is +2. however, under specific experimental conditions, it can lose another electron from the next valence shell. in such a situation the ion formed has +3 electropositive valency. determination of valencies of elements from the formula of compounds we know that the valency of chlorine...
Valency is the combining capacity of the elements to form compounds. During the formation of the molecules of the compounds, atoms combine in certain fixed proportions. Visit BYJUS to learn more about it.