An iron fence post is coated in a layer of zinc. Over time, the fence post becomes deeply scratched, exposing the underlying iron to rainwater and oxygen. Even though the iron is exposed, it does not rust.
Explain why the iron has not rusted.
97 exam-style questions on Edexcel GCSE Chemistry 6.1 Transition metals, alloys and corrosion, covering 6.1.1 Properties of transition metals, 6.1.2 Corrosion and its prevention, and 6.1.3 Alloys and the uses of metals. Each one has a worked solution and a mark scheme showing where the marks go.