Question

An element X occurs in short period having configuration ${ns}^2{np}^1$. What is the formula and nature of its oxide?

Answer 1

We are given an element having electronic configuration as $ns62n{p}^1$ with means that the valency of element $X$ is $3$.

We know than valency of oxide is $2$

Hence the formula becomes $X_2{O}_3$

From the electronic configuration it invisible that the element belongs to $A$ group of periodic table.