A greenhouse full of tomato plants is kept closed during a sunny day. The table shows the percentages of carbon dioxide and oxygen in the air inside the greenhouse at the start and at the end of the day.
| Gas | Percentage at start of day | Percentage at end of day |
|---|---|---|
| Carbon dioxide | 0.060 | 0.025 |
| Oxygen | 20.910 | 20.945 |
Explain how photosynthesis by the plants could account for the changes shown in the table. Use the data and the balanced symbol equation for photosynthesis in your answer.
79 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.