Diamond & Graphite

• Two substances made from the same element, that are in the same physical state, but that have different structures, are called allotropes
• allotropes of solid carbon:

  • diamond
  • graphite
• • Diamond and graphite are examples of giant covalent molecular structures. 
  • Both are made from the element carbon arranged into a large regular repeating lattice
• structure of diamond:

  • Each carbon atom is bonded to 4 other carbon atoms
• structure of diamond

  
• structure of graphite

  
• • the carbon atoms in graphite each bond to 3 other carbon atoms.
  • This arranges the graphite into 2D layers made up of repeating hexagons
• • Graphite is able to conduct electricity.
  • This is because each carbon atom has one delocalised electron, which can move freely, and so is able to carry charge