Which one of the following arrangements represents the correct order of electron gain enthalpy of the given atomic species?

Options

A. `Cl lt F lt S lt O`
B. `O lt S lt F lt Cl`
C. `S lt O lt Cl lt F`
D. `F lt Cl lt O lt S`

Answer

B

Explanation

Halogens have very high electron affinities. It may be noted that the electron affinity of fluorine is unexpectelly low `(lt Cl)` . This may perhaps be due to the small size of the `F` atom. The values of electron gain enthapies for `Cl,F,S,` and `O` are respectively `349,333,200` and `142 kJ//mol` hence order is `ClgtFgtSgtO`.