metals and alloys

• Metallic bonding


  Strong electrostatic attraction between a sea of delocalized negative electrons and positive metal ions
• Metals


  • Consist of a giant structure of atoms arranged in regular layers
  • Outer electrons are delocalized and free to move
• Delocalized electrons in metals

  Allows them to be excellent conductors of heat and electricity
• Alloy


  A mixture of metals where the different sizes of atoms distort the layers, making it more difficult for them to slide over each other
• Alloys


  Are harder than pure metals
• Pure metals like copper, gold, iron and aluminium are not hard enough to be useful on their own
• Making alloys makes metals harder and more useful