Which of the following has the highest electron affinity?

Options

(a) F⁻
(b) O⁻
(c) O
(d) Na

Correct Answer:

O

Explanation:

As the size of atom decreases, a larger amount of energy is released when an elctrn is added to an isolated gaseous atom. Among the given species, the size of O atom is smallest (Since, size of parent atom is smaller as compared to its anion), thus its elctrn affinity is highest.