Which element has the highest electron affinity?

Fluorine has the highest electron affinity among the elements listed because it is located in the upper right corner of the periodic table, where elements tend to have strong tendencies to gain electrons and form anions. Electron affinity is defined as the amount of energy released when an electron is added to a neutral atom in the gas phase.

Fluorine, being a halogen, has a high electronegativity and a strong inclination to attract electrons due to its small atomic radius and effective nuclear charge. When an electron is added to a fluorine atom, it experiences a significant electrostatic attraction to the nucleus, which results in a high release of energy and thus, a high electron affinity.

In contrast, other options such as carbon, sodium, and chlorine exhibit lower electron affinities than fluorine. Carbon has a relatively lower electron affinity due to its lack of completeness in its second electron shell, while sodium, being an alkali metal, has a low tendency to gain an electron as it prefers to lose one to achieve stability. Chlorine, although possessing a high electron affinity, does not exceed that of fluorine. Fluorine’s electron configuration and position in the periodic table make it the element with the highest electron affinity.