Bonding

• Metallic Structure


  Metals consist of giant structures of atoms arranged in a regular pattern
• Metallic Bonds


  Electrons in the outer shell of metal atoms are lost, and individual metal atoms are held together by strong metallic bonds forming a lattice structure
• Delocalised Electrons


  The valence electrons no longer belong to any specific metal atom and are said to be delocalised, meaning they can move freely between the positive metal ions and act like a "sea of electrons"
• Metallic Bonds


  • Very strong, result of the attraction between the positive metal ions and the negative delocalised electrons within the metal lattice structure
• Metals


  • Have very high melting and boiling points, are solids at room temperature (except mercury), usually insoluble in water although some do react with it, good conductors of heat and electricity, layers of atoms can slide over each other making them malleable and able to be hammered and bent into shapes or rolled into flat sheets
• Metals and metal alloys are mixtures of metal
• Alloys


  Mixtures of metals where the metals are mixed together physically but are not chemically combined, can also be made from metals mixed with non-metals such as carbon
• Alloys


  • Can have properties very different to the metals they contain, such as greater strength, hardness or resistance to corrosion or extreme temperatures
• Alloys


  • Contain atoms of different sizes, which distorts the regular arrangement of atoms in the metallic structure
• Electrical Conductivity

  • Metals have free electrons available to move and carry charge through the metal lattice structure
  • Free electrons can also be called mobile or delocalised
  • Electrons entering one end of the metal cause a delocalised electron to displace itself from the other end
  • Hence electrons can flow so electricity is conducted
  • Copper is used extensively in the production of electrical wiring due to its excellent malleability and electrical conductivity