Diamond, Graphite, Fullerenenes & Nanoparticles

• Giant covalent structures are very strong and have high melting and boiling points because we'd have to break all of the strong covalent bonds to melt them
• Giant covalent structures generally don't conduct electricity because they don't contain any charged particles even when they're molten
• Allotropes


  Different structural forms of the same element in the same physical state
• Silicon dioxide (silica)


  • Main component of sand
  • Made of silicon and oxygen atoms in a ratio of 1 to 2
• Allotropes of carbon


  • Diamond
  • Graphite
  • Fullerenes
  • Graphene
• Diamond


  • Giant covalent structure
  • Each carbon atom is covalently bonded to four other carbon atoms
  • Very strong
  • High melting point
  • Does not conduct electricity
• Graphite


  • Giant covalent structure
  • Each carbon atom is covalently bonded to three other carbon atoms
  • Arranged in hexagons forming flat sheets
  • Sheets are weakly held together
  • Relatively soft
  • High melting point
  • Conducts electricity and heat
• Delocalized electrons


  Electrons that are free to move around in graphite
• Graphene


  A single layer of graphite
• Scientists can isolate individual layers of graphite (graphene) and use them to make other structures such as spheres and tubes
• These other structures made from graphene are called fullerenes
• Allotropes


  Different structural forms of the same element in the same physical state
• Graphene


  • Made up of layers
  • Structure of multiple repeating hexagons
  • Each carbon bonded to 3 other carbons
  • Donates one electron to a delocalized pool
  • Can conduct electricity