Question

Which of the above represents the formula for the most common compound of $X$ and $Y$ ? Where $X$ is $N$ and $Y$ is $H$.

• A. $X_{2}Y$
• B. $XY$
• C. $X{Y}_2$
• D. $X{Y}_3$
• E. $X{Y}_4$

Answer 1

Answer: (D)

$X{Y}_3$

$XY$${}_3$ represents the formula for the most common compound of $X$ and $Y$.
$X$ and $Y$ represent $N$ (trivalent) and $H$ (monovalent).
So they form ammonia $NH$${}_3$ or $XY$${}_3$.