Venus is a planet with no life. The table shows the composition of three mixtures of gases.
| Gas | Gases released by a volcano today (%) | Atmosphere of Venus today (%) | Earth's atmosphere today (%) |
|---|---|---|---|
| Carbon dioxide | 40 | 96.5 | 0.04 |
| Water vapour | 55 | trace | varies |
| Nitrogen | 3 | 3.5 | 78 |
| Oxygen | 0 | 0 | 21 |
| Other gases | 2 | trace | about 1 |
Statement 1: The data are consistent with the idea that the Earth's early atmosphere was mainly carbon dioxide and water vapour from volcanoes.
Statement 2: Venus has almost no water vapour, so the Earth's early atmosphere cannot have contained water vapour.
Statement 3: The data suggest that most of the oxygen in the Earth's atmosphere today did not come from volcanoes.
Which statements are supported by the data?
1 only
1 and 3 only
2 and 3 only
1, 2 and 3
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.