Fluorine has a lower size than chlorine, which means there is less attraction outside the shell to gain an electron. In addition, inter-electronic repulsions exist in the 2p orbitals, resulting in a lower negative electron gain enthalpy.
Explain why the electron gain enthalpy of fluorine is less negative than that of chlorine.
Explain why the electron gain enthalpy of fluorine is less negative than that of chlorine.