Allotropes of carbon

Allotropes:

Different structural forms of the same element 

• A Fullerene is a simple molecule
• It is formed when each carbon atom is covalently bonded with three other carbon atoms.
• Often forms tubular molecules(nanotubes) or spherical structures (Buckminister fullerene-C60 i.e 60 carbon atoms forms a ball)
• Weak intermolecular forces having low melting points.
• Weak forces makes them soft + slippery (Lubricant)

• It is not a simple molecule
• Consists of a sheet of carbon with no fixed formula.
• Sheet is one atom thick--making it very light
• covalently bonded--making it extremely strong
• Allows electrons to freely move across its surface--making it a good electrical conductor

• Giant molecular covalent structure
• 3D networks of carbons covalently bonded
• Each carbon atom is covalently bonded with 3 carbon atoms forming a hexagonal sheet
• sheets are held together by weak forces of attraction allowing the layers to slide past each other-- making it a good lubricant(soft/slippery)
• Layered stucture--so not all of the electrons are covalently bonded. Delocalised electrons are free to move to carry electron--conducts electricity--used as electrodes
• High melting points due to strong covalent bonds
  
• Cheap and very unreactive

• Giant molecular covalent structure
• 3D rigid network of carbon atoms in a tetrahedral arrangement
• Each carbon atom is covalently bonded with 4 other carbon atoms
• Strong covalent bonds having high melting points
• No charged particles/delocalised electrons so it is a good elecrical insulator
• Strong so its useful for cutting tools.