Question

Why is fluorine the most electronegative element even though chlorine has greater negative electron gain enthalpy?

Answer 1

electro negativity is directly proportion of z effective and S character .

and inversly proportional of size .

here fluorine size small and z effective and S character more.

so fluorine Is more electro negative.

Answer 2

HEY !!! HEREIS YOUR ANSWER

Fluorine is highly electronegative. It has a great affinity for the electrons but is not capable of being stable by taking an electron. Wheareas Chlorine has its vaccant d orbitals to give enough vaccancy for the electrons & to be stable. Thus, electron gain enthalpy that denotes stability after gaining electron is higher for the Chlorine than for the Fluorine.

HOPE IT HELPS ^_^