Chemistry - PERIODIC TABLE Question with Solution | TestHub

The order of radius of$13\mathrm{th}$group elements is$\mathrm{Ga}<\mathrm{Al}<\mathrm{In}<\mathrm{Tl}$.
Reason$\Rightarrow$Due to poor shielding effect of$\mathrm{d}$-orbital, radius of$\mathrm{Ga}$is smaller than$\mathrm{Al}$.