diamonds and graphite

• Allotropes

  Two substances made from the same element, that are in the same physical state, but that have different structures
• Diamond and graphite are examples of

  giant covalent molecular structures
• Both (diamond and graphite) are made from the element 

  carbon
• diamond and graphite are arranged into a large regular repeating 

  lattice
• diamond bond - carbon atoms

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

  each carbon atom is bonded to 4 other atoms via covalent bonds. 

  This forms a regular 3D lattice which is very strong, and has very high melting and boiling points.
• Can diamond conduct electricity?

  no
• graphite structure

   the carbon atoms in graphite each bond to 3 other carbon atoms.

  This arranges the graphite into 2D layers made up of repeating hexagons.
• can graphite conduct electricity

  yes
• how can graphite conduct electricity

  because each carbon atom has one delocalised electron, which can move freely, and so is able to carry charge.
• why is graphite softer than diamond

  the 2D layers of graphite stack on top of each other with only weak intermolecular forces holding them together.the layers can slide over each other, making graphite easier to break.