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Carbon dioxide is one of the gases in the Earth's atmosphere - Edexcel - GCSE Chemistry - Question 5 - 2019 - Paper 1
Question 5
Carbon dioxide is one of the gases in the Earth's atmosphere. The percentage of carbon dioxide in the Earth's atmosphere has changed over time. (i) Which row of the... show full transcript
Worked Solution & Example Answer:Carbon dioxide is one of the gases in the Earth's atmosphere - Edexcel - GCSE Chemistry - Question 5 - 2019 - Paper 1
Step 1
Which row of the table shows the approximate percentage of carbon dioxide thought to be in the Earth's early atmosphere and how this percentage changed to form the Earth's atmosphere today?
Answer
The correct row is:
| approximate percentage of carbon dioxide in the Earth's early atmosphere | change in percentage carbon dioxide to form the Earth's atmosphere today? |
|---|---|
| C | 95 |
This indicates that approximately 95% of carbon dioxide was present in the Earth's early atmosphere, and it has decreased to form the current atmosphere.
Step 2
Explain two factors that cause the percentage of carbon dioxide in today's atmosphere to vary.
Answer
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Human Activities: The burning of fossil fuels for energy, industrial processes, and deforestation are significant contributors to the rise in carbon dioxide levels. These activities release large amounts of CO2, increasing its concentration in the atmosphere.
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Natural Processes: Natural events such as volcanic eruptions and variations in photosynthesis due to seasonal changes also affect carbon dioxide levels. For instance, during the growing season, plants absorb more CO2, while in winter, decomposition processes may release CO2 back into the atmosphere.