2.36 understand the sacrificial protection of iron in terms of the reactivity series

The sacrificial method involves placing a more reactive metal (such as zinc) with the iron. Water and oxygen then react with the sacrificial metal rather than the iron (as its more reactive than the iron).

Zinc is often used as it is more reactive than iron, so zinc will be oxidised instead of iron. A coating of zinc could be sprayed onto the iron object (galvanising). Another method is to bolt big blocks of zinc onto the iron (e.g. a ships hull of under groups iron pipes).