the atmosphere

Question 1

how many years has the earths atmosphere been how it is today

Answer 1

200 million years

Question 2

what is the percentage of oxygen in the atmosphere

Answer 2

20%

Question 3

what is the percentage of nitrogen in the atmosphere today

Answer 3

80%

Question 4

apart from nitrogen and oxygen which other gases make up our atmosphere today

Answer 4

carbon dioxide, water vapour, noble gases

Question 5

how old is earth

Answer 5

4.6 billion years

Question 6

how long did it take for volcanoes to create the earths atmosphere

Answer 6

1 billion years

Question 7

which gases were present in the earths early atmosphere

Answer 7

carbon dioxide(large amount) methane and ammonia(small amounts) no oxygen

Question 8

which 2 planets are like earths early atmosphere

Answer 8

mars and venus

Question 9

how many carbon dioxide levels decreased

Answer 9

dissolves in oceans, formed rocks, fossil fuels and photosynthesis

Question 10

how have oxygen levels increased as the earths atmosphere developed

Answer 10

photosynthesis by algae and plants

Question 11

how many years ago did algae begin producing oxygen for photosynthesis

Answer 11

2.7 billion years ago