What makes iron nails rust?
Iron rusts when it reacts with water and oxygen. Some iron nails and other iron products do not rust because they are painted, coated in plastic or galvanized (coated in oil) to protect the metal from reacting with water and oxygen and rusting. Some iron products are use sacrificial metals- they are coated in another more reactive metal- to prevent rusting. Iron nails can rust even if they do not come into contact with water because of moisture in the air.
