Iron objects left outdoors become covered in rust. Which pair of substances from the environment must both be present for iron to rust?
Carbon dioxide and water
Nitrogen and oxygen
Oxygen and water
Carbon dioxide and nitrogen
118 exam-style questions on AQA GCSE Chemistry 10.3 Using materials, covering 10.3.1 Corrosion and its prevention, 10.3.2 Alloys as useful materials, and 10.3.3 Ceramics, polymers and composites. Each one has a worked solution and a mark scheme showing where the marks go.