Range of compuonds found in coal, petroleum and natural gas. and the physical properties and uses of carbon and diamond

Physical Properties of Graphite and Carbon

Graphite


Graphite is soft and black and the stable form of carbon. The usual form of graphite (hexagonal graphite) has hexagon sheets arranged in parallel layers. The carbon atoms are found at the corners of the regular and fused hexagons and has three neighbouring carbon atoms, so that the carbon forms a 2-dimensional hexagon net.

The covalent bonding between the sheets are weak and are easily broken as shown above in the diagram thus graphite is a good lubricant as the sheets slide over each other.







Diamond


Diamond is hard and transparent and is the unusual form of carbon. The structure of diamond consists of a regular 3-dimensional array of carbon atoms in which each carbon is situated at the centre of a regular tetrahedron. It is hard because of the strong covalent bonding, the tetrahedral bonds are fully covalent and do not like to be stretched. Moreover the covalent bonds have a 3-dimension...