Which observation is used as evidence that the Earth's early atmosphere was mainly carbon dioxide?
Gases released by volcanoes today contain a lot of carbon dioxide.
The Earth's atmosphere today contains about 78% nitrogen.
Carbon dioxide is a greenhouse gas that absorbs infrared radiation.
Plants today take in carbon dioxide for photosynthesis.
51 exam-style questions on OCR GCSE Chemistry 6.3 Interpreting and interacting with earth systems, covering 6.3.1 Formation and evolution of the atmosphere, 6.3.2 The greenhouse effect and climate change, 6.3.3 Sources and problems of atmospheric pollutants, and 6.3.4 Producing potable water. Each one has a worked solution and a mark scheme showing where the marks go.