Photo AI
The Earth’s early atmosphere was different from that of the Earth’s atmosphere today - Edexcel - GCSE Chemistry Combined Science - Question 1 - 2016 - Paper 1
Question 1
The Earth’s early atmosphere was different from that of the Earth’s atmosphere today. (a) The Earth’s early atmosphere was formed by A animals breathing. B glo... show full transcript
Worked Solution & Example Answer:The Earth’s early atmosphere was different from that of the Earth’s atmosphere today - Edexcel - GCSE Chemistry Combined Science - Question 1 - 2016 - Paper 1
Step 1
Identify the Earth's early atmosphere formation
Answer
The Earth's early atmosphere was primarily formed by D volcanic activity. This is supported by the high percentage of gas X (95%) and the presence of gases like ammonia and sulfur dioxide, which are typically produced by volcanic eruptions.
Step 2
Explain the identity of gas X
Answer
Gas X, constituting 95% of the Earth’s early atmosphere, likely represents carbon dioxide (CO₂). The data indicates a significant decrease in its abundance (to 0.04%) in today's atmosphere. The reduction aligns with the processes of photosynthesis, where plants absorb CO₂, and its storage in sedimentary formations over geological time. Given that carbon dioxide was prevalent during the Earth's early history due to volcanic activity, it is reasonable to conclude gas X is CO₂.