Preventing rusting by using sacrificial protection
2 marks · NormalDescribe how sacrificial protection prevents iron from rusting.
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A more reactive metal is attached to iron; the more reactive metal corrodes in place of the iron.
Also accept: A more reactive metal (such as zinc or magnesium) is attached to the iron; this metal reacts with oxygen and water instead of the iron, so the iron does not rust.
Common mistakes: Stating that sacrificial protection covers the iron with a barrier only.
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Marking points
B1 · 1 mark · Mentions attachment/use of a more reactive metal to protect iron.
B2 · 1 mark · States that the more reactive metal corrodes/reacts instead of the iron (iron does not rust).
Worked solution
A piece of a more reactive metal, such as zinc or magnesium, is attached to the iron. The more reactive metal reacts with oxygen or water instead of the iron, so the iron does not rust.