Corrosion

• corrosion is the breakdown of metal due to reactions with chemicals in its environment. most metals corrode
• sometimes, corrosion is beneficial. some metals form protective oxides on its surface when exposed to the air
• rust is produced when metals containing iron corrodes. the rust is porous and flakes away easily, which exposes fresher steel to corrosion, and this continues until the metal is eaten away
• for rust to form, steel must be exposed to oxygen (air) and water. salt doesn't cause rust, but can accelerate it
• to protect from corrosion, you can;

  1. use a covering of paint, chrome, or plastic
  2. use corrosion-resistant materials
  3. galvanizing (adding a protective layer of zinc to steel, which then protects the steel from corrosion due to the zinc forming an oxide layer)