topic 9 - chemistry of the atmosphere (1. evolution of the atmosphere)

Question 1

how long has the earths atmosphere stayed to same

Answer 1

200 million years

Question 2

what are the main gases in our atmosphere

Answer 2

nitrogen and oxygen

Question 3

state the percentages of the gases in our atmosphere

Answer 3

nitrogen (80%)
oxygen(20%)
other smaller amounts of gases like co2, water vapour and noble gases

Question 4

how was the early atmosphere like

Answer 4

mostly co2 with no o2, like mars and Venus today. volcanic activity leads to the release of nitrogen, water vapour, methane and ammonia.

Question 5

how were oceans formed

Answer 5

water vapour in the atmosphere condensed and formed oceans

Question 6

how was co2 removed from the atmosphere

Answer 6

absorption by the oceans- oceans are a natural store of carbon dioxide. the co2 dissolved into the oceans. when a series of reactions occurred to form carbonate precipitates and then sediments on the seabed co2 were used up from the atmosphere.
absorption by plants and algae - photosynthesis

Question 7

what is the phtosynthesis formula

Answer 7

co2 + water = glucose + oxygen

light