(P2) Atmospheric Science

Question 1

What gases did the earth’s early atmosphere contain?

Answer 1

Little to no oxygen, lots of carbon dioxide, water vapour and small amounts of other gases

Question 2

What gases does the modern atmosphere contain?

Answer 2

78% nitrogen, 21% oxygen and 1% of other gases including water vapour and CO2

Question 3

How did oxygen start to build up in the atmosphere?

Answer 3

Water vapour condensed and formed oceans, life evolved in ocean and photosynthesis begins, oxygen levels rise in oceans and atmosphere

Question 4

How did the formation of oceans cause carbon dioxide to decrease in the atmosphere?

Answer 4

CO2 dissolved in oceans, organisms used it to make calcium carbonate for shells, shells of dead organisms fell to ground and formed sediment, over millions of years the sediment becomes squashed and forms sedimentary rock

Question 5

How does the greenhouse effect reduce the amount of heat radiated into space, keeping the earth warm?

Answer 5

Greenhouse gases in the atmosphere absorb heat radiated from the earth. The gases then release this energy in all directions

Question 6

Name two greenhouse gases and their typical source

Answer 6

Carbon dioxide (burning fossil fuels)
Methane (livestock farming)