Cl has higher electron affinity than E This is due to small size of fluorine. As a result of its very
small size the interelectronic repulsions in relatively compact 2p-sub-shell of chlorine atom. On
comparing chloride ion with fluoride ion we find
that electron density per unit volume in fluoride
ion is more than in chloride ion. This
means that coming electron in fluorine atom finds less attraction than in chlorine atom. Consequently, electron affinity of chlorine is higher than that of fluorine.