Question

Why does fluorine exhibit an anomalous behaviour as compared to the behaviour of other halogens?

Answer 1

1. Fluorine has a very small atomic size, leading to high electron density, which affects its electron gain enthalpy.
2. It is the most electronegative element, only showing an oxidation state of −1, unlike others that show multiple positive states.
3. Fluorine lacks vacant d-orbitals, so it cannot expand its octet or show higher oxidation states.
4. It has unusually low \[\ce{F - F}\] bond dissociation energy, making it highly reactive.
5. Fluorine forms hydrogen bonds in its hydrides, unlike other halogens.
6. Fluorides tend to be ionic, while other halides are more covalent.
7. Fluorine does not form polyhalide ions due to the absence of vacant d-orbitals.