Question

What is the valency of phosphorus in $P{H}_3$?

• A. $-1$
• B. $+2$
• C. $+3$
• D. $-4$

Answer 1

The correct option is C $+3$

The valence (or valency) of an element is a measure of its combining power with other atoms when it forms chemical compounds or molecules.
In $P{H}_3$, $P$ is combined to 3 $H$ atoms, so the valency of phosphorous is $+3.$