The correct order of covalent radii of $Si$,$Ge$,and $Sn$ is:

The size of isoelectronic species $F^{-},$ $Ne$ and $Na^{+}$ is affected by
$(a)$ Nuclear charge $(Z)$
$(b)$ Valence principal quantum number $(n)$
$(c)$ Electron-electron interaction in the outer orbitals
$(d)$ None of the factors because their size is the same.

Given below are two statements $ : $
Statement $(I) :$ The metallic radius of $Al$ is less than that of $Ga$.
Statement $(II) :$ The ionic radius of $Al^{3+}$ is less than that of $Ga^{3+}$.
In the light of the above statements, choose the most appropriate answer from the options given below $ : $

Which of the following ions has the smallest radius?

Explain the measurement methods of atomic radius.

In which of the following options,elements are correctly arranged in the increasing order of their atomic radius?