Which of the following has the highest electron affinity?

Options

A. `F_(2)`
B. `Cl_(2)`
C. `Br_(2)`
D. `I_(2)`

Answer

B

Explanation

On moving down the group electron affinity must decrease. because of the increase in the size of the atom. However, fluorine has lower electron affinity than chlorine. A low value of electron affinity for fluorine is due to the small size of F-atom. In a compact 2 p-orbltals of F, the added electron does not feel much attraction, because of inter electronic repulsion between the electrons already present in small compact 2 p-subshell of F-atom.