Question

Fluorine is a better oxidising agent than chlorine although the its electron gain enthalpy is less than Cl.Why?

Answer 1

Oxidizing agents are the atoms of those substances which can easily gain electrons to reduce the negative charge of another atom.

Size of fluorine is smaller than chlorine, so nuclear pull on the valence electrons of fluorine is comparatively more than the nuclear pull on valence electrons of chlorine. So, fluorine can more easily accept an electron from another atom than chlorine...hence fluorine is a better oxidizing agent.