Question

Arrange S, Cl and F in order of decreasing electron affinity. Cl > F > S F > Cl > S F > S > Cl Cl > S > F

Answer 1

The correct order of decreasing electron affinity is:

Cl > F > S

- The electron affinity becomes more negative upon moving from left to right across a period.

- So, chlorine has more electron affinity than sulphur.

-  The electron affinity becomes less negative upon moving from top to bottom in a group.

- Chlorine should have a less electron affinity than chlorine but it is not the case.

- In fact, fluorine has a less negative electron affinity than chlorine because of its small size and hence more repulsion.

- So, the correct order becomes Cl > F > S.