2.35 describe how the rusting of iron may be prevented by grease, oil, paint, plastic and galvanising

Preventing rusting

Coating iron with:

• grease
• oil
• paint 
• plastic
• a metal less reactive than iron, such as tin

2.34 describe the conditions under which iron rusts

Rusting of iron

Rusting is a chemical reaction between iron, water and oxygen. Rusting takes place faster if there are also electrolytes such as sodium chloride in the water. NaCl is present in sea water.

Iron atoms have been oxidised as they have lost 3 electrons.