The correct order of ionic size of $N^{3-}$,$Na^{+}$,$F^{-}$,$Mg^{2+}$,and $O^{2-}$ is:

On going down a main sub-group in the periodic table (example $Li$ to $Cs$ in $IA$ or $Be$ to $Ra$ in $IIA$),the expected trend of changes in atomic radius is a

Increasing order of ionic size for the ions,$F^{-}$,$O^{2-}$,$Na^{+}$,$Al^{3+}$ is :-

Explain why cations are smaller and anions larger in radii than their parent atoms.

Which of the following is the incorrect order of ionic/atomic radius?

Assertion $(A)$: $Mg^{2+}$ and $Al^{3+}$ are isoelectronic but the magnitude of the ionic radius of $Al^{3+}$ is less than that of $Mg^{2+}$.
Reason $(R)$: The effective nuclear charge on the outermost electrons in $Al^{3+}$ is greater than that in $Mg^{2+}$.
The correct option among the following is: