Giant covalent structures and fullerenes

• Giant covalent structures consist of lots of atoms held together by covalent bonds.
• They are arranged into giant lattices, which are extremely strong because of the large number of bonds in the structure
• They have very high melting and boiling points as lots of energy is needed to break the covalent bonds.
• They generally don't contain charged particles, so they don't conduct electricity (apart from graphene and graphite)
• Diamond- made of a network of carbon atoms held together by four strong covalent bonds. These bonds take lots of energy to break so has a high melting point. Held in a rigid lattice structure, diamond is very hard (used to strengthen cutting tools). It doesn't conduct electricity because it has no free electrons or ions.
• Graphite- three covalent bonds between each carbon atom, so it is held together by weak forces, creating sheets of carbo atoms aranged in hexagons. There aren't any covalent bonds between the layers- they are only held together weakly, so they're free to move over each other, this makes graphite soft so its ideal as a lubrication metal. High melting point- covalent bonds in the layers need loads of energy to break. Graphite has one free electron so it can conduct electricity.
• Graphene: a form of carbon consisting of planar sheets which are one atom thick (making it 2D), with the atoms arranged in a hexagon-shaped lattice. It has delocalised electrons which make it an excellent electrical conductor.
• Fullerenes: Molecules made of carbon atoms arranged in hollow tubes. They can be used to 'cage' other molecules, can be used to deliver a drug inside the body. They have a huge surface area, so they can make great industrial catalysts.
• Nanotubes: Strong (high tensile strength), flexible, conduct electricity, lightweight (can be used to strengthen materials without adding much weight), and a good thermal conductor.