The unit representing atomic radii and ionic radii is

Which one of the following species possesses maximum size?

Atomic radii of fluorine and neon in $\mathring{A}$ units are respectively given by

Identify the isoelectronic species from the following groups.

If four different elements $A, B, C$ and $D$ have electronic configurations as $A = [Ne] 3s^2 3p^4$,$B = [Ne] 3s^2 3p^5$,$C = [Ar] 3d^{10} 4s^2 4p^4$ and $D = [Ar] 3d^{10} 4s^2 4p^5$,identify the element with the largest atomic radius.

Chloride ion $(Cl^-)$ and potassium ion $(K^+)$ are isoelectronic. Then: