The ionic radius of sodium ion (Na+) is smaller than the atoric radius of sodium atom. True or False ? See a detailed explanation by us you can give your contributions using the comment section (True) A sodium atom loses an electron to become the sodium ion (Na —> Na* + e). This loss of electron causes an imbalance between the positive nuclear charge and the remaining electrons. Thus, the positive nuclear charge pulls in the remaining electrons closer and reduces the ionic radius of Na* below that of the atomic radius.