Question

Arrange the following elements in the order of their increasing electron affinity.

• A. Iodine
• B. Bromine
• C. Fluorine
• D. Chlorine

Answer 1

As the atomic size increases down the group, the electron affinity generally decreases. But the electron affinity of chlorine is higher than that of fluorine. Since fluorine has a smaller size than chlorine, the electron-electron repulsion is very high, which resists the addition of any further electron to the atom. Thus the electron affinity follows the order – iodine < bromine < fluorine < chlorine.