Anomalous behaviour of fluorine

Fluorine, the first member of group 17, differs in properties from the other members of the group. The anomalous behaviour of fluorine is due to the following reasons:

i. small atomic size

ii. high electronegativity

iii. absence of d-orbitals in the valence shell

iv. low F-F bond dissociation enthalpy

Some anomalous properties of fluorine :

i. Ionisation enthalpy, electronegativity and electrode potential are all higher for fluorine than the expected trends shown by the other halogens.

ii. Ionic and covalent radii, m.p., b.p. and electron gain enthalpy are quite lower than expected.

iii. Most of the reactions of fluorine are exothermic (due to the short and strong bond formed by it with other elements). …