The Evolution of the Atmosphere

This lesson covers:

  1. The formation of the early atmosphere by volcanic activity 
  2. How the atmosphere changed with the formation of the oceans
  3. How living organism made the atmosphere more suitable for life

Roughly how old is the planet Earth?

Around 4.6 billion years old

Around 13.7 billion years old

Around 2.7 billion years old

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Illustration of the Earth with clouds representing the atmosphere.

Which gas makes up around 80% (78.09% to be exact) of the Earth's atmosphere?

Oxygen

Argon

Nitrogen

Carbon dioxide

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Which gas makes up around 20% (20.95% to be exact) of the Earth's atmosphere?

Carbon dioxide

Argon

Oxygen

Nitrogen

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Which of the gases below contribute less than 1% to the Earths atmosphere?

(Select all that apply)

Argon

Carbon dioxide

Nitrogen

Oxygen

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In the first billion years, the gases that formed Earth's early atmosphere came mainly from which source?

Burning of fossil fuels 

Volcanic activity

Photosynthesis by plants and algae

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Illustration of the Earth with volcanoes erupting and releasing gases.

During the first billion years, which two of the following gases were released from volcanoes?

Water vapour

Carbon dioxide 

Oxygen

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Cooling of the Earth


dissolved / cool / warm / sediments / condense / oceans / carbonates 


  1. Around a billion years after it formed, the earth began to . This allowed water vapour to into liquid water and form the
  2. When the oceans formed, carbon dioxide in the water, and were precipitated, producing .
  3. Steps 1 & 2 dramatically reduced the amounts of water vapour and carbon dioxide in the atmosphere.
cool
condense
oceans
dissolved
carbonates
sediments

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Starting 2.7 billion years ago, which process started to increase the amount of oxygen in the atmosphere, and further decreased the amount of carbon dioxide?

Volcanic activity

Burning of fossil fuels 

Photosynthesis by plants and algae

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Illustration of a seedling growing in soil with sunlight, representing photosynthesis.

Complete the word equation for photosynthesis:


carbon dioxide +  ➔ oxygen +

water
glucose

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As photosynthetic organisms such as plants and algae died, the carbon they contained became trapped in rocks, and fuels.

sedimentary
fossil

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