The correct order of atomic radii of given elements is

Which one of the following is the smallest in size?

The correct order of the atomic radii of $C, Cs, Al$ and $S$ is

The radii of $F$,$F^{-}$,$O$ and $O^{2-}$ are in the order of:

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:

What are the covalent and van der Waals radii in $Cl_2$?