The radii of ions are always smaller than the radii of the corresponding atoms of the same element.

Question

Quizplus · Accepted Answer

When an atom loses electrons to form a cation, its radius decreases due to a decrease in electron-electron repulsion and an increase in the effective nuclear charge per electron. However, when an atom gains electrons to form an anion, its radius increases due to increased electron-electron repulsion outweighing the increase in effective nuclear charge. Therefore, the radii of anions are larger than the radii of the corresponding neutral atoms.

The Radii of Ions Are Always Smaller Than the Radii