Graphite is a giant covalent molecule. This means it has many atoms joined together by covalent bonds. Graphite consists of layers of carbon atoms joined together by covalent bonds with delocalised electrons between layers. The delocalised electrons can carry charge which allows graphite to conduct electricity. As there are only weak forces in between layers they are able to slide over each other. Therefore graphite is soft. The strong covalent bonds require a lot of energy to overcome and therefore graphite has a high melting point and is insoluble in water and solvents.