Allotropes of Carbon

• Diamond is a giant covalent structure.
• Diamond structure - each carbon atom forms four covalent bonds with other carbon atoms
• Diamond has a high melting point because of strong bonds.
• Diamond cannot conduct electricity because it has no charged particles that are free to move
• Graphite - Each carbon atom forms three covalent bonds with other carbon atoms
• In Graphite the carbon atoms form layers of hexagonal rings. There are no covalent bonds between the layers.
• Graphite has delocalised electrons, just like metals.
• Graphite can conduct electricity because delocalised electrons are free to move between layers.
• Graphene is a single layer of graphite.
• Graphene - The strong covalent bonds between the carbon atoms give it a very high melting point and is very strong.
• Graphene conducts electricity well because it has delocalised electrons that are free to move across its surface.
• Fullerenes are molecules of carbon atoms with hollow shapes.
• Buckminsterfullerene was the first fullerene to be discovered
• The structure of fullerenes is based on hexagonal rings of carbon atoms but they may also contain rings with five/seven carbon atoms.
• A nanotube is a fullerene in a cylinder shape
• Nanotubes are strong and conduct electricity because they have delocalised electrons.
• Carbon nanotubes are cylindrical fullerenes with very high length to diameter ratios.
• Nanotubes can be used for nanotechnology, electronics, vaccines and cancer treatment.