Metallic Bonding

Metallic bonding involves delocalised electrons

• Metals also consist of a giant structure
• The electrons in the outer shell of the metal atoms are delocalised
  • There are strong forces of electrostatic attraction between the positive metal ions and the shared negative electrons
• These forces of attraction hold the atoms together in a regular structure and are known as metallic bonding
  • Metallic bonding is very strong
• Substances that are held together by metallic bonding include metallic elements and alloys
• It’s the delocalised electrons in the metallic bonds which produce all the properties of metals

Most metals are solid at room temperature

• The electrostatic forces between the metal atoms and the delocalised sea of electrons are very strong, so need lots of energy to be broken
• This means that most compounds with metallic bonds have very high melting and boiling points, so they’re generally solid at room temperature

Metals are good conductors of electricity and heat

• The delocalised electrons carry electrical current and thermal energy through the whole structure, so metals are good conductors of electricity and heat

Most metals are malleable

• The layers of atoms in a metal can slide over each other, making metals malleable, this means that they can be bent or hammered or rolled into flat sheets

Alloys are harder than pure metals

• Pure metals often aren’t quite right for certain jobs, they’re often too soft when they’re pure so are mixed with other metals to make them harder
• Most of the metals we use everyday are alloys, a mixture of two or more metals or a metal and another element
  • Alloys are harder and so more useful than pure metals
  • Different elements have different sized atoms, so when another elements is mixed with a pure metal, the new metal will distort the layers of metal atoms, making it more difficult for them to slide over each other