# Why do the halogen atoms have the greatest electron affinity?

$X \left(g\right) + {e}^{-} \rightarrow {X}^{-} \left(g\right) + \Delta$
Halogen have the greatest nuclear charge, and in addition such reduction COMPLETES their valence shell to give a stable 8-electron configuration. Negative vales for $\Delta$ would be anticipated.