Question

Largest in size out of $N{a}^{+},O^{2-}$ and $F^{-}$ is?

• A. $N{a}^{+}$
• B. $O^{2-}$
• C. $F^{-}$
• D. All are equal

Answer 1

The correct option is B $O^{2-}$

Atomic size decreases with increase in effective nuclear charge and increases with the addition of a new shell. Here $O^{2-}$ and $F^{-}$ have one shell more than $N{a}^{+}$ and effective nuclear charge on $F^{-}$ is more than $O^{2-}$.