The Earths Atmosphere Flashcards
1
Q
What percentage of oxygen was in the early atmosphere
A
21%
2
Q
What % of nitrogen was in the early atmosphere
A
78%
3
Q
What % of co2 was in the early atmosphere
A
0.04%
4
Q
What was the earth when it first formed
A
A molten ball of rock covered in volcanoes
5
Q
What do volcanoes release
A
Carbon dioxide, methane, ammonia, water vapor
6
Q
How are oceans formed
A
When water vapours condense and icy commits melt
7
Q
Why do oxygen levels increase
A
Photosynthesising algae and replacing carbon dioxide with oxyen
8
Q
What evidence is there for oxygen
A
Iron pyrite- break down in presence of oxygen - ancient rocks
9
Q
Where did all the co2 go
A
- Photosynthesis
- Co2 dissolved in the oceans and formed insoluble carbonate rocks
