Metals and alloys

• Metallic bonding


  The bonding in metals where the outer electrons are delocalized and free to move through the whole structure
• Metals


  • Consist of a giant structure of atoms arranged in regular layers
  • Have delocalized outer electrons that are free to move through the whole structure
• Delocalized electrons


  Electrons in the outer energy level of each metal atom that are not attached to any individual atom, but are free to move through the whole structure
• Positive metal ions


  The metal atoms that have lost their outer electrons
• Metallic bond


  The strong electrostatic attraction between the sea of delocalized negative electrons and the positive metal ions
• High melting and boiling points of metals

  Due to the need to break the strong metallic bonds, which requires a great deal of energy
• Metals


  • Excellent conductors of heat and electricity due to the delocalized electrons that can move and carry electric current and thermal energy
• Metals


  • Can be bent and shaped because the layers of atoms can slide over each other
• Alloy


  A mixture of metals where the different sizes of atoms distort the layers, making it more difficult for the layers to slide over each other, resulting in the alloy being harder than pure metals
• Pure metals like copper, gold, iron and aluminium are not hard enough to be useful on their own, so alloys are made to make them harder