Question

Name 3 non-metals or groups of non-metals which have valency of -1, -2 & -3 respectively?

Answer 1

Non metals with valency
-1= Fluorine (F)
-2= Oxygen (O)
-3= Nitrogen (N)

Answer 2

The groups of non metals which have the above valencies are
1)Valency -1   7A Group(F,Cl,Br,I,As)
2)Valency  -2   6A Group(O,S,Se,Te,Po)
3)Valency -3   5 A group(N,P,As,Sb,Bi)
Hope it helps you