Rusting is the chemical corrosion of iron.
Oxygen is one of the two key substances required for iron to rust.
Give the name of the other substance required for iron to rust.
Practise Edexcel GCSE Chemistry Transition metals, alloys and corrosion with exam-style questions for Foundation and Higher tier. 97 questions, matched to the Edexcel GCSE Chemistry (1CH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
