Bonding, structure & the properties of matter

• ions are charged atoms, that have either gained or lost electrons
• ionic bonding happens between a metal and a non-metal element, where they transfer electrons
• covalent bonding occurs between non-metal elements, where they share electrons
• metallic bonds consist of a sea of negative electrons surrounded by positive ones
• a Polymer is a long chain of a repeating Monomer
• larger Polymers have stronger intermolecular forces, and therefore are harder to break
• the common allotropes of Carbon are - diamond, graphite, graphene and fullerene
• diamond -

  • four covalent bonds
  • the strong covalent bonds require a lot of energy to break so it has a high melting point
  • it does not conduct electricity
• graphite -

  • three covalent bonds
  • the layers are held together weakly, so they can slide around - can be used as a lubricating material
  • covalent bonds need a lot of energy to break - high melting point
  • it conducts electricity
• Graphene -

  • a sheet of Carbon atoms
  • one atom thick - two dimensional
  • it can conduct electricity
  • the two covalent bonds make it very strong but also very light
• Fullerenes are molecules of Carbon, shaped like closed tubes of hollow balls