C1.1

Question 1

How was the early atmosphere formed?

Answer 1

Gases escaped from volcanoes

Question 2

What did the early atmosphere contain?

Answer 2

Very little oxygen

large amounts of carbon dioxide and water vapour

Question 3

Why is it difficult for scientists to investigate early atmosphere gases?

Answer 3

No humans around at this time so nothing could be measured, evidence can come to many different conclusions

Question 4

How were oceans formed?

Answer 4

Water vapour condensed

Question 5

How did CO2 levels falls?

Answer 5

Dissolved into oceans, some sea animals took in CO2 to make their shells.

Question 6

How did oxygen levels increase?

Answer 6

More plants photosynthesising gave out oxygen

Question 7

Current atmosphere gases?

Answer 7

78% nitrogen 21% oxygen 1% argon 0.03% carbon dioxide

Question 8

What causes changes in the atmosphere?

Answer 8

Volcanoes erupt - releasing CO2
Burning fossil fuels - Releases C02
Deforestation- amount of C02 being taken in is reduces
Farming - more cows increase methane

Question 9

What’s the word equation of photosynthesis?

Answer 9

CO2 + water = glucose + oxygen