Question

Among the following, the isoelectronic species is/ are:
(i) $O^{2-},F^{-},N{a}^{+},M{g}^{2+}$
(ii) $N{a}^{+},M{g}^{+},A{l}^{3+},F^{-}$
(iii) $N^{3-},O^{2-},F^{-},Ne$

• A. (i) and (ii)
• B. (i), (ii) and (iii)
• C. (ii) and (iii)
• D. (i) and (iii)

Answer 1

The correct option is D (i) and (iii)

Isoelectronic species are those species which have same number of electrons.

Among the options,

$O^{2-}=10$ electrons

$F^{-}=10$ electrons

$N{a}^{+}=10$ electrons

$M{g}^{2+}=10$ electrons

And, $N^{3-},O^{2-},F^{-}$ and $Ne$ have $10$ electrons each.

So, option (i) & (iii) have isoelectronic species.