Allotropes of Carbon - Diamond and Graphite

• What are the two allotropes of carbon discussed in the video?

  Diamond and graphite
• What are allotropes?

  Different structural forms of the same element
• In what physical state are the allotropes of carbon being discussed?

  Solid state
• What type of structures are diamond and graphite?

  Giant covalent structures
• What is the arrangement of atoms in diamond?

  Each carbon bonded to four others
• Why is diamond very strong?

  It has strong covalent bonds
• What is the melting point characteristic of diamond?

  Very high melting point
• Why does diamond not conduct electricity?

  No free electrons or ions present
• How many carbon atoms does each carbon atom in graphite bond to?

  Three other carbon atoms
• What is the arrangement of atoms in graphite?

  Hexagons forming large flat sheets
• How are the layers in graphite held together?

  Weakly, with no covalent bonds
• What property of graphite allows it to be relatively soft?

  Layers can slide over one another
• Does graphite have a high melting point?

  Yes, it has a very high melting point
• What happens to the spare electron in graphite?

  It becomes delocalized and free to move
• What do the delocalized electrons in graphite allow it to do?

  Conduct electricity and heat
• What is a single layer of graphite called?

  Graphene
• What can scientists do with isolated layers of graphene?

  Use them to make other structures
• What are the key differences between diamond and graphite?

  • Diamond:
  • Each carbon bonds to four others
  • Strong covalent bonds
  • Very high melting point
  • Does not conduct electricity
  • Graphite:
  • Each carbon bonds to three others
  • Weakly held layers
  • Very high melting point
  • Conducts electricity and heat
• What are the implications of the structures of diamond and graphite on their properties?

  • Diamond's strong covalent bonds lead to:
  • High strength
  • High melting point
  • Non-conductivity
  • Graphite's layered structure leads to:
  • Softness
  • High melting point
  • Electrical conductivity