Graphite

Graphite has a giant covalent structure in which:

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  • each carbon atom forms three covalent bonds with other carbon atoms
  • the carbon atoms form layers of hexagonal rings
  • there are weak forces of attraction between the layers
  • there is one, non-bonded – or delocalised – electron for each atom

Graphite’s properties include:

  • high melting and boiling points. Graphite’s many covalent bonds are strong and substantial energy is needed to break them.
  • good electrical conductivity. Each carbon atom has an unbonded electron. The unbonded electrons are delocalised electrons that are free to move and carry charge.
  • softness. The weak forces between graphite’s layers allow them to slide.

Graphite is used as a lubricant and in pencils.

Graphite sheetThe dotted lines represent the weak forces between the layers in graphite.