Scientists think that most of the gases in the Earth's early atmosphere were released by volcanoes.
Which finding, if it were true, would most weaken this idea?
Volcanoes erupting today release mainly water vapour and carbon dioxide
The oldest rocks contain minerals that only form when there is no oxygen
Gas trapped in the oldest rocks is mostly a gas that volcanoes hardly release
The early oceans formed when water vapour in the atmosphere condensed
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.