The correct order of the ionic radii of
Question:

The correct order of the ionic radii of

$\mathrm{O}^{2-}, \mathrm{N}^{3-}, \mathrm{F}^{-}, \mathrm{Mg}^{2+}, \mathrm{Na}^{+}$and $\mathrm{Al}^{3+}$ is :

1. $\mathrm{Al}^{3+}<\mathrm{Na}^{+}<\mathrm{Mg}^{2+}<\mathrm{O}^{2-}<\mathrm{F}^{-}<\mathrm{N}^{3-}$

2. $\mathrm{N}^{3-}<\mathrm{O}^{2-}<\mathrm{F}^{-}<\mathrm{Na}^{+}<\mathrm{Mg}^{2+}<\mathrm{Al}^{3+}$

3. $\mathrm{Al}^{3+}<\mathrm{Mg}^{2+}<\mathrm{Na}^{+}<\mathrm{F}^{-}<\mathrm{O}^{2-}<\mathrm{N}^{3-}$

4. $\mathrm{N}^{3-}<\mathrm{F}^{-}<\mathrm{O}^{2-}<\mathrm{Mg}^{2+}<\mathrm{Na}^{+}<\mathrm{Al}^{3+}$

Correct Option: , 3

Solution:

Correct order of size for isoelectronic species.

$\mathrm{Al}^{3+}<\mathrm{Mg}^{2+}<\mathrm{Na}^{+}<\mathrm{F}^{-}<\mathrm{O}^{2-}<\mathrm{N}^{3-}$