Limestone is a sedimentary rock. The carbon in limestone was once carbon dioxide in the Earth's atmosphere.
Name the main compound in limestone.
Describe how limestone was formed from carbon dioxide that was once in the atmosphere.
Give one other rock or fuel that stored carbon which was once carbon dioxide in the atmosphere.
40 exam-style questions on AQA GCSE Chemistry 9.1 The composition and evolution of the Earth's atmosphere, covering 9.1.1 The proportions of different gases in the atmosphere, 9.1.2 The Earth's early atmosphere, 9.1.3 How oxygen increased, and 9.1.4 How carbon dioxide decreased. Each one has a worked solution and a mark scheme showing where the marks go.