C9 - Chemistry of The Atmosphere

Question 1

what are the proportions of gases in the atmosphere

Answer 1

80% nitrogen
20% oxygen
very small proportions of other gases including CO2, water vapour, noble gases

Question 2

why is evidence for the early atmosphere limited

Answer 2

the time scale

Question 3

what is the first theory about the earths atmosphere

Answer 3

during the first billion years of the earths existance, there was an intense volcanic activity that released gases that formed the early atmosphere

Question 4

what was the earths atmosphere believed to have been similar to

Answer 4

that of mars and venus, consisting of mainly CO2 and little to no oxygen

Question 5

what did volcanoes produce that built up in the atmosphere

Answer 5

nitrogen and small proportions of ammonia and methane

Question 6

what produced the oxygen that is now in the earths atmosphere

Answer 6

algae and plants by photosynthesis

Question 7

give the word equation and symbol equation for photosynthesis

Answer 7

carbon dioxide + water —> glucose + oxygen
6CO2 +6H2O —-> C6H12O6 + 602

Question 8

when did algae first produce oxygen and how did the percentage of oxygen increase to a level that allowed plants to evolve

Answer 8

about 2.7b years ago
plants evolved

Question 9

2 ways the level of CO2 was decreased in the atmosphere

Answer 9

algae and plants by photosynthesis
formation of sedimentary rocks and fossil fuels that contain carbon

Question 10

what was the second theory ab the earths atmosphere

Answer 10

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

Question 11

what was the 3rd theory about the earths atmoshphere

Answer 11

that green plants and algae made oxygen

Question 12

how are fossil fuels like coal and crude oil made

Answer 12

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

Question 13

how is crude oil made

Answer 13

formed by deposits of plankton. they form when they get trapped in reservoirs under the seabed when they get trapped in rocks

Question 14

how is coal made

Answer 14

a sedimentary rock made from thick plant deposits

Question 15

how is limestone made

Answer 15

made of calcium carbonate deposits from the shells and skeletons of marine organisms

Question 16

why are greenhouse gasses in the atmosphere useful

Answer 16

they maintain tempreatures on the earth high enough to support life

Question 17

explain why greenhouse gasses warm up the earth

Answer 17

as they absorb the long wavelength radiation that gets reflected back off earth and re-readiate. this long wavelength radiation is thermal radiation

Question 18

what human activities increase the amounts of carbon dioxide

Answer 18

burning fossil fuels

Question 19

based on peer reviewed evidence, what do sceicntist believe will cause the temp of the Earths atmosphere to increase

Answer 19

human activities

Question 20

what is a major cause of climate change

Answer 20

increase in average global tempreature

Question 21

give 4 effects of climate change

Answer 21

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

Question 22

what is a carbin footprint

Answer 22

the total amount of carbon dioxide and other greenhouse gases emitted over the full cycle of a product, service or event

Question 23

how can we reduce carbon emissions

Answer 23

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

Question 24

why may it be hard to reduce carbon footprints

Answer 24

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

Question 25

what may form particulates in the atmosphere

Answer 25

solid particles and unburned hydrocarbons

Question 26

how can carbon monoxide be produced

Answer 26

when fossil fuels are burned in incomplete combusition

Question 27

why are particualtes bad

Answer 27

cause health problems in humans
bad for enviroment as they cause global dimming

Question 28

why is carbon monoxide bad

Answer 28

it binds to haemoglobin in the blood so less oxygen is able to be transported around the bodu

Question 29

why is carbon monoxide bad

Answer 29

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

Question 30

when is sulfur dioxide released

Answer 30

combustion of fossil fuels containing sulfur impurities

Question 31

why is sulfur dioxide and nitrogen oxide mixing bad

Answer 31

as they make dilute sulfuric acid or dilut nitric acid making acid rain
respiatory problems