The ionic radius is:

In which of the following pairs is the second atom larger than the first?

Which of the following represents the correct order of atomic radii?

Identify the pair of elements in which the difference in atomic radii is maximum.

Which of the following is the correct order of ionic radii for ${N^{3-}}, {O^{2-}}, {F^-},$ and ${Na^+}$?

Given below are the pairs of group $13$ elements showing their relation in terms of atomic radius: $(B < Al)$, $(Al < Ga)$, $(Ga < In)$ and $(In < Tl)$. Identify the elements present in the incorrect pair and in that pair,find out the element $(X)$ that has a higher ionic radius $(M^{3+})$ than the other one. The atomic number of the element $(X)$ is: