The Early Atmosphere

Question 1

How were the gases produced that formed the earths early atmosphere?

Answer 1

volcanic activity

Question 2

Did the earths early atmosphere contain a little or a lot of oxygen?

Answer 2

Little

Question 3

Did the earths early atmosphere contain a little or a lot of carbon dioxide?

Answer 3

A lot

Question 4

Besides oxygen and carbon dioxide what other gases made up the earths early atmosphere?

Answer 4

A lot water vapour, small amounts of: ammonia, methane, nitrogen and small amounts other gases.

Question 5

Explain why there are different sources of information about the development of the atmosphere which makes it difficult to be precise about the evolution of the atmosphere.

Answer 5

There were no humans around to measure the atmosphere, so they have to use clues. There are different sources of information, but not all the evidence leads to the same conclusion. this means that it is difficult to know exactly what the early atmosphere was like and how it has changed.

Question 6

How were oceans formed?

Answer 6

Condensation of water vapour

Question 7

How did condensation of water vapour form oceans?

Answer 7

Billions of years ago the atmosphere started to cool down which caused the large amounts of water vapour in the atmosphere to condense and form clouds. The clouds then rained so much that they produced oceans.

Question 8

What was the reason as to why the large amount of carbon dioxide decreased after oceans were formed?

Answer 8

The dissolution of carbon dioxide into the oceans.

Question 9

How did the levels of oxygen gradually increase in the earths early atmosphere?

Answer 9

After the oceans were formed, forms of life such as plants began to evolve which lead to photosynthesis beginning, the oxygen then builds up in the ocean which leads to it building up in the atmosphere.

Question 10

How did the levels of carbon dioxide gradually decrease in the earths early atmosphere? Also how did it then lead to sedimentary rocks being formed?

Answer 10

After the oceans were formed, carbon dioxide started to dissolve into it. After that the marine organisms then used the dissolved carbon dioxide to make calcium carbonate for shells. Then, the shells of dead marine organisms fall to the bed and become part of the sediment. Finally, over millions of years the layers of sediment become squashed and form sedimentary rocks.