What is the structural difference between diamond and graphite?
There are many structural differences between diamond and graphite, due to which they show different physical properties.
In diamond, each C atom is bonded with 4 other C atoms i.e. each carbon atom is tetravalent. While in graphite, each C atom is bonded to 3 other C atoms i.e. each carbon atom is trivalent.
In diamond there is 3-D cross linked network of C atoms, with shape of every set of C atom is tetrahedral while in graphite the shape of the structure is hexagonal, with every side of hexagon representing a C atom.
In diamond every layer of C atom is bonded with strong sigma bonds, while in graphite different layers of C atoms are bonded with weak Van-der-Waal forces.
Diamond doesn’t have any valence electron left after bonding with other 4 C atoms, while in graphite each C atom is bonded with 3 other C atoms, so it has a mobile electron due to which it conduct electricity and heat.
In diamond every C atom is sp3 hybridised, while in graphite every C atom is sp2 hybridised.