The oldest sedimentary rocks on Earth contain iron(II) compounds but no iron(III) oxide. Newer rock layers, formed later, contain significant bands of iron(III) oxide.
Explain what happened to Earth's atmosphere to allow these iron(III) oxide bands to form.
Practise Edexcel GCSE Chemistry Earth and atmospheric science with exam-style questions for Foundation and Higher tier. 62 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.
