Rusting

• What is corrosion?

  The process by which metals are slowly broken down by reacting with substances in their environment
• What are the two methods of preventing rusting?

  Barrier Sacrificial
• What are barrier methods?

  Preventing oxygen and water from touching the iron e.g. paint it, oil it, electroplating
• What are sacrificial methods?

  Adding a more reactive metal to iron e.g. galvanising
• What is galvanising?

  The process of applying a protective layer of zinc to iron to prevent rusting
• What is the word equation for rusting?

  Iron + Water + Oxygen -> Hydrated Iron Oxide
• What is needed for iron to rust?

  Oxygen and Water
• Why doesn't aluminium rust?

  • reacts with oxygen very quickly
  • creates a thin layer of aluminium oxide on its surface
  • stops oxygen from meeting the metal