Corrosion

• Metals

  Shiny elements that are good conductors of electricity and heat, and which form basic oxides
• Oxidation

  Chemical substances are oxidised by the addition of oxygen, removal of hydrogen or the removal of electrons
• Reactive

  The tendency of a substance to undergo a chemical reaction
• Corrosion

  1. Metals continue to oxidise

  2. Metal becomes weaker over time

  3. Metal may become metal oxide
• Rusting


  Corrosion process in which iron or steel reacts with oxygen and water
• Iron or steel object

  Only rusts if oxygen and water are present
• Hydrated iron(III) oxide is the orange-brown substance seen on the surface of rusty objects
• Calcium chloride (in the right-hand test tube) absorbs water
• The nail does not rust in the middle test tube, where there was water but no oxygen (because there was no air in the water)
• The nail does not rust in the right-hand test tube, where there was oxygen (air) but no water
• When iron forms rust

  It is oxidised
• Formula of rusting:

  Iron + Oxygen + Water —> Hydrated iron (III) oxide