Question

An element $\text{X}$ forms an oxide ${\text{XO}}_3$. What can be the valency of element $\text{X}$?

• A. 5
• B. 6
• C. 2
• D. 4

Answer 1

The correct option is B 6

The compound ${\text{XO}}_3$ has three atoms of oxygen.

Valency of one oxygen atom = 2
Valency of three oxygen atoms = 2 x 3 = 6

A molecule is overall neutral in charge. So, the valencies of the ions must balance each other while writing a chemical formula.

So, the valency of $\text{X}$ can be 6.