A student studying electron-capture species for a gas-phase detector compares isolated gaseous fluorine and chlorine atoms. Electron affinity is reported as the magnitude of the energy released when one mole of gaseous atoms each gains an electron.

Atom	Valence configuration before electron addition	Energy released \(\text{(kJ/mol)}\)
\(\text{F(g)}\)	\(2s^2 2p^5\)	\(328\)
\(\text{Cl(g)}\)	\(3s^2 3p^5\)	\(349\)

Which statement best explains the relative electron affinities of the two atoms?