Question

An atom of an element A has three electrons in its outer shell and B has six electrons in its outermost shell.The formula of the compound formed between these two will be-?

Answer 1

A has three electrons in its outer shell. So it is a metal n its valency will be 3
B has six electrons in its outermost shell. So it is a nonmetal n its valency will be 2.

So formula of the compound formed will be A2B3.