The ionic radius of chloride ion (CI) is smaller than the atomic radius of chlorine atom. True or False ? see a detailed explanation by us you can give your contributions using the comment section (False) A chlorine atom gains an element to become the chloride ion (CI + e -+ CI). With this added negative charge, the effective nuclear charge has been reduced and thus the inner electron repulsion increases. This makes the ionic radius of CI to increase beyond the atomic radius of CI.