Question

If $N_A$ is Avogadro’s number then number of valence electrons in $4.2g$ of nitride ions $\left(N^{3-}\right)$

• A. $2.4N_A$
• B. $4.2N_A$
• C. $1.6N_A$
• D. $3.2N_A$

Answer 1

Answer: (A)

$14gm{N}^{3-}$ ions have $8N_A$. valence electrons
$4.2gm$ of $N^{3-}$ ions have $=\frac{8N_A\times 4.2}{14}=2.4N_A$