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Chemistry:Atmosphere

Key questions on the early atmosphere

QuestionAnswer
How long have the proportions of the gases in the atmosphere been like today? 200 million years
What are the gases found in today's atmosphere? Nitrogen, Oxygen, Carbon Dioxide, Water Vapour, Noble gases
What are the percentages of the gases in today's atmosphere? 80% Nitrogen , 20% Oxygen , less than 1% other gases
What planets is the earth's early atmosphere suggested to be like? Mars and Venus, consisting mainly of carbon dioxide and little or no oxygen
What other gas were released by volcanoes? Nitrogen , Methane, Ammonia
How were Carbon Dioxide levels reduced? Dissolved in oceans Locked in fossil fuels Plants carry out photosynthesis
Why did the percentage of oxygen increase in the early atmosphere? Algae and plants released it during photosynthesis
When did algae first appear ? 2.7 billion years
What did the increase in oxygen from algae and plants lead to? Enabled animals to evolve
Created by: beth.dawkin
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