C9 - Chemistry of The Atmosphere Flashcards
what are the proportions of gases in the atmosphere
80% nitrogen
20% oxygen
very small proportions of other gases including CO2, water vapour, noble gases
why is evidence for the early atmosphere limited
the time scale
what is the first theory about the earths atmosphere
during the first billion years of the earths existance, there was an intense volcanic activity that released gases that formed the early atmosphere
what was the earths atmosphere believed to have been similar to
that of mars and venus, consisting of mainly CO2 and little to no oxygen
what did volcanoes produce that built up in the atmosphere
nitrogen and small proportions of ammonia and methane
what produced the oxygen that is now in the earths atmosphere
algae and plants by photosynthesis
give the word equation and symbol equation for photosynthesis
carbon dioxide + water —> glucose + oxygen
6CO2 +6H2O —-> C6H12O6 + 602
when did algae first produce oxygen and how did the percentage of oxygen increase to a level that allowed plants to evolve
about 2.7b years ago
plants evolved
2 ways the level of CO2 was decreased in the atmosphere
algae and plants by photosynthesis
formation of sedimentary rocks and fossil fuels that contain carbon
what was the second theory ab the earths atmosphere
that oceans, algae and plants absorbed cO2
in the oceans, it went through a series of reactions to form carbon precipitates that formed sediments on the sea bed
what was the 3rd theory about the earths atmoshphere
that green plants and algae made oxygen
how are fossil fuels like coal and crude oil made
when plants, plankton and marine animals die, they fall to the seabed and get buried by layers of sediments. over millions of years, they become compressed and form sedimentary rocks and they trap the carbon inside of them
how is crude oil made
formed by deposits of plankton. they form when they get trapped in reservoirs under the seabed when they get trapped in rocks
how is coal made
a sedimentary rock made from thick plant deposits
how is limestone made
made of calcium carbonate deposits from the shells and skeletons of marine organisms
why are greenhouse gasses in the atmosphere useful
they maintain tempreatures on the earth high enough to support life
explain why greenhouse gasses warm up the earth
as they absorb the long wavelength radiation that gets reflected back off earth and re-readiate. this long wavelength radiation is thermal radiation
what human activities increase the amounts of carbon dioxide
burning fossil fuels
based on peer reviewed evidence, what do sceicntist believe will cause the temp of the Earths atmosphere to increase
human activities
what is a major cause of climate change
increase in average global tempreature
give 4 effects of climate change
polar ice caps melting causing a rise in sea level and flooding
changes in rainfall patterns meaning it may affect the ability to produce food
more storms and more severe
changes in temp and water avaliable in a habitat may affect wild species
what is a carbin footprint
the total amount of carbon dioxide and other greenhouse gases emitted over the full cycle of a product, service or event
how can we reduce carbon emissions
using renewable energy sources
using more efficient processes
taxing companies based on how much greenhouse gasses they emit
put a cap on all emissions of greenhouse gasses
using technology to capture CO2
why may it be hard to reduce carbon footprints
governments worried about how making changes will impact economic growth
as not everyone agrees so its hard to make international agreements
people arent educated enough to begin to make changes
what may form particulates in the atmosphere
solid particles and unburned hydrocarbons
how can carbon monoxide be produced
when fossil fuels are burned in incomplete combusition
why are particualtes bad
cause health problems in humans
bad for enviroment as they cause global dimming
why is carbon monoxide bad
it binds to haemoglobin in the blood so less oxygen is able to be transported around the bodu
why is carbon monoxide bad
it binds to haemoglobin in the blood so less oxygen is able to be transported around the body
not easily detected as colourless and odorless
when is sulfur dioxide released
combustion of fossil fuels containing sulfur impurities
why is sulfur dioxide and nitrogen oxide mixing bad
as they make dilute sulfuric acid or dilut nitric acid making acid rain
respiatory problems
