1 (a) The two most common gases in today's atmosphere are nitrogen and oxygen - Edexcel - GCSE Chemistry - Question 1 - 2020 - Paper 1
Question 1
1 (a) The two most common gases in today's atmosphere are nitrogen and oxygen.
(i) What is the third most common gas in today's atmosphere?
A argon
B butane
C c... show full transcript
Worked Solution & Example Answer:1 (a) The two most common gases in today's atmosphere are nitrogen and oxygen - Edexcel - GCSE Chemistry - Question 1 - 2020 - Paper 1
Step 1
What is the third most common gas in today's atmosphere?
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Answer
The third most common gas in today's atmosphere is argon (A).
Step 2
What is the percentage of oxygen in today's atmosphere?
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Answer
The percentage of oxygen in today's atmosphere is 21% (B).
Step 3
Give the name of the most common gas in the Earth's early atmosphere.
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Answer
The most common gas in the Earth's early atmosphere was carbon dioxide.
Step 4
Explain what caused the amount of water vapour in the atmosphere to decrease.
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The amount of water vapour in the atmosphere decreased due to the cooling of the Earth, which led to condensation and the formation of oceans.
Step 5
Calculate the increase in the concentration, in ppm, of carbon dioxide from January 2018 to January 2019.
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To find the increase: 410.83 ppm (January 2019) - 407.96 ppm (January 2018) = 2.87 ppm. Rounded to the nearest whole number, the increase is 3 ppm.
Step 6
Give a possible cause for this increase in the concentration of carbon dioxide.
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Possible causes for the increase in carbon dioxide concentration include the burning of fossil fuels and deforestation.
