Diamond & Graphite

• Allotrope

  Different physical forms of the same element in the same physical state

  Example: Diamond, graphite and graphene
• In diamonds how many bonds does each carbon atom have

  4
• Structure and bonding of diamond

  Giant covalent lattice structure where each carbon is covalently bonded to 4 other carbon atoms forming a repeating lattice
• Why can’t diamond conduct electricity

  No charged electrons or ions that can move freely throughout the structure
• Properties of diamond

  High melting and boiling points

  Hard

  Doesn’t conduct electricity
• In graphite how many covalent bonds does each carbon atom have

  3
• Structure and bonding of graphite

  Giant covalent lattice structure which is covalently bonded to 3 other carbon atoms forming a sheet of hexagonal rings that are held together by intermolecular forces. It also has delocalised electrons that can flow
• Why can graphite conduct electricity

  It has delocalised electrons that can flow and carry charge
• Properties of graphite

  High melting/boiling point

  Soft and brittle

  Good conductor of heat and electricity
• Why can graphite be used as a lubricant

  Carbon atoms are arranged in layers

  Forces between layers are weak intermolecular forces

  This means they don’t need much energy to break so layers slide over each other easily
• Why does diamonds have a higher melting/boiling point

  Diamond atoms are held together by strong covalent bonds while graphite includes weak intermolecular forces