The ionic radius of `Na^(+)` is less than the atomic radius of Na but the ionic radius of `Cl^(-)` is greater than the atomic radius of Cl-why?

Explanation

The `Na^(+)` ion has 11 protons in its nucleus but it has 10 extranuclear electrons. Since the number of electrons is less than that of protons, there electrons are attracted by the nucleus to a greater extent. Hence, ionic radius of `Na^(+)` is smaller than that of Na having the same number of protons (11) and electrons (11). on the other hand, the `Cl^-` ion has 17 protons in its nucleus but it has 18 extranuclear electrons. since the number of protons is less than that of electrons, the electrons are not strongly attracted by the nucleus. in order to be relieved of the strain of the electron-electron repulsion, the electron cloud gets more diffused. hence, the ionic radius of `Cl^(-)` is greater than the atomic radius of Cl.