Question

EXPLAIN the following trend and anomalies observed on the electron affinities of elements in the halogen family in the periodic table.

Electron affinity generally decreases from top to bottom down a group, but it increases slightly from fluorine (-328 kJ) to chlorine (-349 kJ). Why does fluorine has lower electron affinity than chlorine?

Answer 1

chlorine electron affinity higher than fluorine . the reason is that small atomic size fluorine. in fluorine there are three lone pair of electrons in its outermost shell . there is will be some repulsions among already existed lone pairs . so incoming electron acceptance is less favor compared to chlorine .in chlorine the atomic size is larger so the lone pairs can accommadate at sufficient distance so the repulsions are minimized in chlorine so it can readily accept electron ,so that its electron affinity is greater