allotropes of carbon

• Diamond

  • Formed from CARBON ATOMS each sharing four COVALENT BONDS in a rigid, three-dimensional structure.
  • DIAMOND is very hard, with a high melting point. This is because of the LARGE NETWORK of covalent bonds that require a LARGE AMOUNT of ENERGY to overcome.
  • It does not conduct electricity as it has NO FREE MOVING ELECTRONS OR IONS.
• Graphite

  • Composed of LAYERED structures of HEXAGONAL RINGS, with each carbon atom bonded to THREE other atoms with COVALENT BONDS.
  • Carbon has FOUR electrons in its outer shell, so the fourth electron that is NOT used for bonding is DELOCALISED.
  • This means GRAPHITE is a good CONDUCTOR of electricity, as its delocalised electrons can carry a charge (just like metals).
  • It is SOFT, and used as a LUBRICANT due to weak forces between layers, causing the layers to SLIDE over one another.
• Graphene

  • Graphene ia a SINGLE LAYER of graphite, and is strong and light.
  • It is a good CONDUCTOR of HEAT and ELECTRICITY due to its DELOCALISED ELECTRONS, so is used in ELECTRONICS and composite materials.
• Fullerenes


  Molecules with hollow shapes, such as spheres or tubes
• Structure of fullerenes


  • Based on hexagonal rings of Carbon atoms
  • May also contain rings with five or seven Carbon atoms
• Uses of fullerenes


  • Drug delivery
  • Industrial catalysts
• Buckminsterfullerene


  A spherical fullerene with a formula of C60
• Carbon nanotubes


  Cylindrical fullerenes with very high length to diameter ratios
• Properties of carbon nanotubes

  • Useful for nanotechnology, electronics and materials
  • Good conductors of heat and electricity
  • Have delocalised electrons
  • Can be used in electronics and nanotechnology
  • High tensile strength without much mass
  • Useful for certain materials, such as the ones used in tennis rackets