A student sets up an experiment to investigate the corrosion of iron. They place an iron nail into a test tube containing tap water and leave it exposed to the air. After several days, an orange-brown layer of rust forms on the nail.
Which gas from the air has reacted with the iron nail to cause this rusting?
Carbon dioxide
Nitrogen
Oxygen
Argon
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.