The table below shows the composition of an exoplanet's early atmosphere compared with its atmosphere today.
| Nitrogen | Oxygen | Carbon dioxide | Helium | |
|---|---|---|---|---|
| Percentage of gas in the early atmosphere (%) | 5 | 1 | 85 | 9 |
| Percentage of gas in the atmosphere today (%) | 92 | 5 | 2 | 1 |
Which gas has changed by the largest percentage (percentage points) from the early atmosphere to the atmosphere today?
Carbon dioxide
Helium
Nitrogen
Oxygen
32 exam-style questions on OCR GCSE Chemistry Interpreting and interacting with earth systems. Each one has a worked solution and a mark scheme showing where the marks go.