Explain why size of cation is smaller than of the parent atom.

Explanation

Cation is formed by the ion of one of more election from the gaseous atom . Now in cat ion the nuclear charge remains the same as that in the parent atom but the number of electrons becomes less . As a result of these , the nucleus hold on the remaining elections increase because of the increase in the effective nuclear change per electron. Thus causes decrease in size , Ex : The relative size of sodium atom and sodium ion is as follows :