Question

An element X forms an oxide $X{O}_3$, the valency of element X is:

• A. 6
• B. $+3$
• C. $+6$
• D. $-6$

Answer 1

The correct option is C

$+6$

The compound $X{O}_3$ has three atoms of oxygen.

Valency of an O atom = $-2$

Charge of three O atoms = $-2\times 3$ = $-6$

The compound needs to be electrically neutral, the valency of X should be $+6$.