The Earth was very hot to start off with, and there were no oceans. As the Earth cooled down the water vapour in the atmosphere condensed to form a liquid water.This liquid water became what?
The oceans
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Why can't scientists be certain about the form of the early atmosphere?
There were no humans around so we must use clues.
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The Earths early atmosphere was formed by gases produced from what?
Volcanoes
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The Earths early atmosphere did not contain what?
Oxygen
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What are the two gases present in the largest amounts in the Earths early atmosphere?
Water vapour and carbon dioxide
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Today the Earths atmospherehas much less than 1% carbon dioxide and has more than 21% oxygen this means that?
Carbin dioxide has been removed from the atmosphereand oxygen has been added to the atmosphere.
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How does oxygen get added to our atmosphere?
The Earth cools and oceans form.Forms of life evolve in the oceans and photosynethesis begins.Oxygen builds up in the oceans.Oxygen builds up in the atmosphere.
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How was carbon dioxide removed from the Earths early atmosphere?
Carbon dioxide dissolved in then oceans and marine organisms used the dissolved carbon dioxide to make calcium carbonate for shells and the shells of the dead marine organisms fall to the sea bed and become part of the sediment.
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What can add carbon dioxide to the atmosphere?
Burning fossil fuels and deforestation
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Other cards in this set
Card 2
Front
Why can't scientists be certain about the form of the early atmosphere?
Back
There were no humans around so we must use clues.
Card 3
Front
The Earths early atmosphere was formed by gases produced from what?
Back
Card 4
Front
The Earths early atmosphere did not contain what?
Back
Card 5
Front
What are the two gases present in the largest amounts in the Earths early atmosphere?
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