question_answer 26)

Give two examples to show the anomalous behaviour of fluorine.

Answer:

The two examples are : (i) Fluorine shows only and oxidation state of –1 due to non-availability of d-orbitals in its velence shell, while all other halogens due to the presence of vacant d-orbitals, show positive oxidation states of +1, +3, +5 and +7 besides oxidation state of –1. (ii) F – F bond dissociation energy is lower than that of Cl-Cl. Bond. This is because of greater repulsion between the lone pairs on the two fluorines due to small size.