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.
97 exam-style questions on Edexcel GCSE Chemistry 9.2 Earth and atmospheric science, covering 9.2.1 The Earth's early atmosphere, 9.2.2 How the atmosphere evolved, 9.2.3 Chemical test for oxygen, and 9.2.4 The greenhouse effect and climate change. Each one has a worked solution and a mark scheme showing where the marks go.