allotropes of carbon

• diamond is very hard as it has a giant covalent structure were each carbon atom forms 4 covalent bonds
• in diamond , strong covalent bonds take a lot of energy to break giving it a high melting point
• diamond cannot conduct electricity because it has no free electrons
• in graphite, each carbon atom forms 3 covalent bonds creating sheets of carbon atoms arranged in hexagons
• in graphite, there are no covalent bonds between layers so layers move freely making graphite soft and slippery so an ideal lubricating material
• graphene is a sheet of graphite which is one atom thick making it a 2d substance
• graphite has high melting point as covalent bonds in layers need lots of energy to break
• graphite conducts electricity as it has one free electron per carbon atom.
• graphenes network of covalent bonds make it strong
• graphene is light so it can be added to composite materials to make them stronger without adding much weight
• graphene has delocalised electrons so can conduct electricity
• fullerenes are molecules of carbon shaped like closed tubes
• fullerenes are mainly made up of carbon atoms arranged in hexagons
• fullerenes can cage other molecules and can be used to carry drug into body
• fullerenes have a large surface area and can be used as catalysts
• fullerenes can form nanotubes which are tiny carbon cylinders
• nanotubes can conduct electricity and thermal energy
• nanotube have high tensile strength