Why does the element silicon, not form a graphite like structure whereas carbon does.

Graphite is a macro molecule which is made up of hexagonal carbon rings. The carbons have sp2 hybridisation and form 2 sigma and one pi bond each. Silicon , being in the same group does have similarities but it does not form macro molecules only with itself like carbon. This is due to the catenation property of the elements. Catenation is the tendency of an element to form covalent bonds with itself . Carbon has the highest catenation tendancy due to which it forms large chains. A reason for silicon having lesser catenation property than carbon is due the their respective bond energies. A C-C bond is very strong, providing high stability to the molecule. however a Si-Si bonds is not so strong. This is why silicon cannot form macro molecules with itself like carbon. read less