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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 D, which states that the approximate percentage of carbon dioxide in the Earth's early atmosphere was 95, and this percentage has decreased to form the Earth’s atmosphere today. This indicates a significant reduction in carbon dioxide levels over geological time.
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: Increased industrialization and burning of fossil fuels have introduced more carbon dioxide into the atmosphere, thus impacting its overall percentage. Activities such as transportation, electricity generation, and deforestation contribute significantly to CO2 emissions.
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Natural Processes: Natural events such as volcanic eruptions, oceanic absorption of CO2, and photosynthesis by plants affect the carbon dioxide levels. For instance, during periods of high volcanic activity, CO2 levels can spike, while plant growth can reduce the amount of CO2 in the atmosphere.