The Earth's sea and atmosphere

Question 1

Where do scientists think the early atmosphere came from?

Answer 1

Erupting Volcanos

Question 2

How did the oceans form?

Answer 2

The earth cooled and the water vapour condensed

Question 3

How did the oceans remove carbon dioxide from the atmosphere?

Answer 3

Carbon dioxide dissolved into the oceans.

Question 4

The carbon dioxide that had dissolved into the oceans was used by some animals. What did they do?

Answer 4

Some animals used it to make their shells. When they died the shells fell to the bottom of the oceans. the shells got covered in sediment and over millions of years they became the sedimentary rock limestone

Question 5

How do plants remove carbon dioxide from the atmosphere?

Answer 5

Plants absorb carbon dioxide and release oxygen. This process is called photosynthesis

Question 6

How was oxygen added to the atmosphere

Answer 6

Plants release oxygen in a process called photosynthesis.

Question 7

What are the gases and the percentage of each in todays atmosphere?

Answer 7

Nitrogen 78%, oxygen 21%, Argon 0.9%, Carbon dioxide 0.04% and traces of other gases.

Question 8

Some natural processes cause small changes in todays atmosphere. What are they?

Answer 8

Volcanoes erupt releasing sulphur dioxide, lightning can produce nitrogen oxides

Question 9

Some human activities cause small changes in todays atmosphere. What are they?

Answer 9

Deforestation, burning fossil fuels, farming cattle and growing rice

Question 10

What is deforestation?

Answer 10

The chopping down of trees. This means that less carbon dioxide can be removed from the atmosphere

Question 11

What gases can be given off by the burning of fossil fuels?

Answer 11

Carbon dioxide, carbon monoxide and sulphur dioxide

Question 12

what gas does cattle farming and the growing of rice give off?

Answer 12

Methane