Question

Which one of the following is smallest in size ?

• A. $O^{2-}$
• B. $F^{-}$
• C. $N{a}^{+}$
• D. $N^{3-}$

Answer 1

The correct option is C $N{a}^{+}$

Among isoelectronic species, the relation in size is
Cation < Neutral < Anion
Hence, $N{a}^{+}$ has the smallest size.