Which of the following ions has the smallest radius?

$Na^{+}$,$Mg^{2+}$,$Al^{3+}$,and $Si^{4+}$ are isoelectronic. Their ionic size follows the order:

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:

Which of the following has the largest size?

Which of the following orders of ionic radii is correctly represented?

Identify the increasing order of the covalent radii of the given elements: $(I) Ti, (II) Ca, (III) Sc$.