Atmosphere

• Early Earth's atmosphere was similar with Mars
• Composition of Earth atmosphere

  • Nitrogen 78%
  • Oxygen 21%
  • Carbon dioxide 0.04%
• Atmosphere


  The mixture of gases around a body in space
• The Earth's atmosphere today contains water, carbon dioxide, nitrogen and oxygen
• It's hard to know what gases are in the atmosphere without testing them because they are colourless and many of them do not have a smell
• Layers of the atmosphere

  • Exosphere
  • Thermosphere
  • Mesosphere
  • Stratosphere
  • Troposphere
• The exosphere has the highest temperature because solar radiation hits it first and is absorbed by particles of gas in it
• Gases in the early atmosphere

  • Ammonia (NH3)
  • Water Vapour (H2O)
  • Carbon Dioxide (CO2)
  • Nitrogen (N2)
• The gases in the early atmosphere were released from volcanoes
• Carbon dioxide is harmful for our planet because it causes global warming, which leads to melting icebergs and flooding
• The composition of the early atmosphere was mostly carbon dioxide, nitrogen and ammonia
• How the atmosphere changed

  1. Volcanoes released gases like water vapour, carbon dioxide, nitrogen and methane to form the early atmosphere

  2. As the Earth cooled, water vapour became liquid to form the oceans, decreasing the amount of water in the air

  3. Carbon dioxide dissolved in the oceans, decreasing the amount in the air

  4. Carbon dioxide was used as a reactant in photosynthesis and plants produced oxygen

  5. Sedimentation locked up carbon in fossil fuels and carbonate compounds
• Ways the amount of carbon dioxide in the atmosphere decreased

  • Dissolved in oceans
  • Used in photosynthesis
  • Sedimentation
• Useful products made from sedimentation

  • Crude oil
  • Coal
  • Limestone
• Gas percentage of early Earth

  • Nitrogen 3%
  • Carbon dioxide 18%
  • Oxygen increased from 0%
• The percentage of oxygen increased because plants released oxygen during photosynthesis
• The amount of carbon dioxide in the air decreased from the early Earth to today due to sedimentation, dissolving in oceans, and being used in photosynthesis