Question

Down a group, electron affinity ______ [increases, decreases, remains same].

Answer 1

Down the group, electron affinity decreases.

Explanation:

As you move down a group, the atomic size increases because new electron shells are continuously added. This places the outermost shell much farther away from the nucleus and increases the shielding effect of the inner electrons. Consequently, the nucleus exerts a weaker attractive force on an incoming electron, resulting in less energy being released when that electron is added.