Question

Which of the folllowing is the correct order of electron affinity?
A. `At lt I lt Br lt F lt Cl`
B. `At lt I lt Br lt Cl lt F`
C. `At lt I lt Cl lt Br lt F`
D. `At lt Br lt I lt Cl lt F`

Answer 1

Correct Answer - 1
Electeon affinities for all the halogens are negative implying that energy is realeased when a halgeon atom gains an electron ,`(X rarr X^(-))`. Thus all halgons form halide ions.
Electron affinity of the group `17` elements becomes less and negative from `Cl` onwards. However mthe elctron affinity of `F` is less negative thatn that of chlorine. Due ot small size of `F` atoms, there are strong interelctronic replusion and hence the incoming electrons does not experience much attraction. Thus correct order is `Cl gt F gt Br gt I gt At`