Question

13Al 14Si 11Na 12Mg which one has smallest atomic radius​

Answer 1

As atomic radius decreases from left to right in a period and increases down the group

So the elements having the smallest atomic radius is Si

Si<Al<Mg<Na

I hope this helps ( ╹▽╹ )

Answer 2

$\huge \red{Answer}$

14Si have the smallest Atomic radius.

$\huge \red{REASON}$

Sodium, magnesium ,aluminium and silicon belongs to 3rd Period of modern periodic table.

In moder periodic table atomic radius decrases while going left to right in period.

This happens because in a period number of shells the elements have is same.But the number of proton and electron increases while going from left to right.This increases the intermolecular attaraction force and radius of atom decreases while going from left to right in modern periodic table.