Question

which has higher electron affinity O or S. why

Answer 1

Dear Student , Sulphur has higher electron affinity , as we know oxygen has small size and high electron density compared to sulphur, interelectronic repulsion is higher in oxygen, resulting in less energy being released when an electron is added to oxygen, due to lesser stability after electron is added, which is due to the interelectronic repulsion in the small oxygen atom. Hence electron affinity value is lower. It is an abnormality and exception to the general periodic trend of electronic affinity values. Regards