C2 - covalent bonding & alleotropes

• name the allotropes of carbon

  graphene

  graphite

  diamond

  fullerenes
• what happens in covalent bonding?


  electrons are being shared
• what are the properties of simple molecular substances?

  low melting/boiling point

  weak intermolecular forces
• give properties of giant covalent structures

  regular repeating lattices

  high melting/boiling points

  do not conduct electricity except graphite/graphene
• give physical properties of diamond

  solid at room temperature

  very hard

  shiny
• give chemical properties of diamond

  high melting/boiling point

  does not conduct electricity

  giant covalent structure
• how many covalent bonds does each carbon atom form in diamond?

  4
• how many covalent bonds does each carbon atom form in graphite/graphene/fullerenes?

  3
• give properties of graphite


  conducts electricity

  made up of layers (flat sheets) - can slide over one another

  giant covalent structure

  high melting/boiling point
• give properties of graphene


  can conduct electricity

  1 layer thick

  strong covalent bonds

  high melting/boiling point
• give uses of nanotubes 


  
  

  • electronics
  • tennis rackets
• give uses of buckminster fullerenes


  drug delivery

  industrial catalysts

  lubricant
• what is a polymer made up of?

  monomers

  covalent compound
• melting/boiling point of polymers?

  lower than giant covalent, higher than simple molecular