C11 Flashcards
1
Q
How was the earths early atomsphere formed
A
By volcanic activity
2
Q
During the early atmosphere times what did it mainly consist of
A
Carbon dioxide, nitrogen and water
3
Q
As plants spread over the earth the level of…
A
The level of oxygen in the atmospjere increased
4
Q
Give two examples of things that removed carbon dioxide form the atmosphere
A
- photosynthesis by algae and plants decreased carbon
- formation of sedimentary rocks and fossil duels that contain carbon
5
Q
Approxamtely how much of the earths atmosphere is made up of nitrogen and oxygen
A
78 percent nitrogen and 21 percent oxygen
