evolution of the atmosphere

Question 1

what was the earth atmosphere like originally

Answer 1

large amounts of carbon dioxide
little to no oxygen
small amounts of other gases such as ammonia and methane

Question 2

what is the earths atmosphere like now

Answer 2

80% nitrogen and 20% oxygen with very little other gases

Question 3

how did carbon dioxide levels drop

Answer 3

due to plants and trees doing photosynthesis

it also dissolved into water and also created lots of rock such as limestone which is very soluble

Question 4

what is the most abundant gas in the atmosphere

Answer 4

nitrogen

Question 5

what are the three main green house gases

Answer 5

water vapour
carbon dioxide
methane

Question 6

what do the green house gases do

Answer 6

they absorb heat radiated by the earth

and reflect it in all directions to keep the earth warm

Question 7

how does the green house effect work

Answer 7

electromagnetic radiation at most wavelengths passes through the Earth’s atmosphere
the Earth absorbs most of the radiation and warms up
the Earth radiates energy as infrared radiation
some of the infrared radiation goes into space
some of the infrared radiation is absorbed by greenhouse gases in the atmosphere
the lower atmosphere warms up

Question 8

name four negative effects of green house gases

Answer 8

glaciers and polar ice melting
sea levels rising
patterns of rainfall changing, producing floods or droughts
habitats changing