The composition of the Earth's atmosphere has changed a great deal over the last 4.6 billion years. For the last 200 million years the proportions of the gases have been much the same as they are today.
Describe and explain the main changes in the composition of the Earth's atmosphere over the last 4.6 billion years.
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.