Question:
The isoelectronic set of ions is :
Correct Option: 1
Solution:
Atomic numbers of $\mathrm{N}, \mathrm{O}, \mathrm{F}$ and $\mathrm{Na}$ are $7,8,9$ and 11 respectively. Therefore, total number of electrons in each of $\mathrm{N}^{3-}, \mathrm{O}^{2-}, \mathrm{F}^{-}$, and $\mathrm{Na}^{+}$are 10 and hence they are isoelectronic.