Question

Fluorine has higher electronegativity but less electron gain enthalpy. Explain.

Answer 1

1. The highest values of electronegativity are seen in halogens because of their high nuclear charge and short atomic radii.
2. Fluorine has the highest electronegativity due to its small size.
3. In fluorine due to strong inter electronic repulsions in the relatively small 2p orbitals and higher electron density, there is not much nuclear attraction for the incoming electron.
4. Thus the electron gain enthalpy of fluorine is less in spite of higher electronegativity.