C13 The atmosphere

Question 1

how was the early atmosphere formed

Answer 1

volcanic eruptions released lots of CO2

Question 2

gases in early atmosphere

Answer 2

mainly CO2
nitrogen and water vapour
traces of methane and ammonia

Question 3

how did oxygen levels increase/ CO2 decrease

Answer 3

oceans formed- water vapour condensed
CO2 dissolved in seawater
removed in photosynthesis
‘locked in’ rocks and fossil fuels
algae photosynthesized- rise in O2

Question 4

atmosphere % now

Answer 4

78% nitrogen
21% oxygen
small portions, CO2, water vapour

Question 5

greenhouse effect

Answer 5

sun emits short electromagnetic wavelengths
surface absorbs wavelengths and cools by emitting longer wavelength infrared radiation
GGs absorb infrared
stimulates molecules, raising their temp

Question 6

consequences of GGs

Answer 6

rising sea levels- melting ice caps
flooding of low lying land
increased coastal erosion
frequent extreme weather events
changes in temp
change in amount, timing and distribution of rainfall
change of distribution of wildlife

Question 7

carbon footprint

Answer 7

total amount of CO2 and other greenhouse gases emitted over its full life cycle

Question 8

hydrocarbon

Answer 8

only hydrogen and carbon atoms
produce carbon dioxide and water when fully oxidised
CO2 + H2O

Question 9

sulfur impurities

Answer 9

burn to form sulfur dioxide
can cause acid rain
sulfur removed from fuels before burning
sulfur dioxide removed from flue gas

Question 10

carbon monoxide

Answer 10

product of incomplete combustion
can cause global dimming