Graphite is used as a lubricant. Explain.

Explanation

(1) In graphite, all the carbon atoms are `sp^(2)`- hybridised.
(2) Each carbon - atom is covalently bonded to three other `sp^(2)` hybridised carbon atoms forming `sigma` bonds, while fourth electron in `2p_(z)` orbitals is used in the formation of `pi` bond . This results in the formation of hexagonal rings in two dimensions.
(3) In graphite, the layers consisting of hexagonal carbon network are held together by weak van der Waals forces. imparting softness.
(4) The layers in graphite can slide over another layer on applying a shearing force, hence it is used as a lubricant and in lead pencils.