Science - Chemistry - Chemistry of the Atmosphere - C9

Question 1

what are the 2 main gases in the atmosphere ?

Answer 1

nitrogen
oxygen

Question 2

what percentage of the atmosphere is nitrogen ?

Answer 2

roughly 80%

Question 3

what percentage of the atmosphere is oxygen ?

Answer 3

roughly 20%

Question 4

what was earth like at the beginning ?

Answer 4

molten, so hot that atmosphere dispersed into space

Question 5

give a timeline of earths atmosphere forming

Answer 5

• earth is molten, too hot atmosphere dispersed into space
• earths atmosphere cooled, so a crust formed but volcanos kept errupting
• lots of volcanic activity- volcanos gave out gas
• the gas given out by volcanos formed the early atmosphere and oceans
• this gas was mainly carbon dioxide with no oxygen, like mars and venus
• volcanic activity released nitrogen which built up atmosphere over time, water vapour, ammonia and methane was also given out
• earth cooled, water vapour condensed, forming oceans

Question 6

why is the earths atmosphere timeline not 100% definate ?

Answer 6

no scientists were there at the time

Question 7

how was carbon dioxide removed from the atmosphere ?

Answer 7

• absorption from atmosphere
  -absorption of green plants and algae
• locking away carbon dioxide

Question 8

how was carbon dioxide absorbed from the atmosphere ?

Answer 8

• it was stored in oceans
• it dissolved in the oceans through a series of reactions to form carbon precipitate which formed sediment on seabeds
• marine animals which died, there shells and skeletons were trapped with carbon from oceans

Question 9

how was carbon dioxide absorbed by green plants and algae ?

Answer 9

by photosynthesis

Question 10

how was carbon locked up ?

Answer 10

• animals who died sank into the seabeds and were buried under sediment which compressed them to form sedimentary rocks, oil and gas trapping carbon within them
• this created fossil fuels formed by deposits of plankton which formed resovoirs under seabed
• limestone is a rock made out of calcium carbonate formed from the deposit of shells and skeletons of dead marine animals which locked up carbon

Question 11

how did the volume of oxygen in the atmosphere increase ?

Answer 11

• produced by photosynthesis
• as oxygen built up, more complex life evolved

Question 12

how is there evidence for the evolution of the atmosphere ?

Answer 12

• volcanos release this gas today
• planets which are less evolved and do not have life such as mars and venus have atmospheres similar to earths early atmosphere
• rocks have iron oxide which are only formed when there was enough oxygen in the atmosphee to react with iron
• living things such as bacteria which doesn’t need oxygen to require was found in old fossil fuels showing there wasn’t much oxygen in the early atmosphere

Question 13

give examples of greenhouse gases ?

Answer 13

methane
carbon dioxide
water vapour

Question 14

what is the greenhouse effect ?

Answer 14

• the sun emits shortwavelength radiation which passes through the earths atmosphere
• this reaches the earths surface is absorbed and re-emmitted as longwave length radiation
• this is absorbed by greenhouse gases
• greenhouse gases re-radiate in all directions even back to earth
• long wave radiation is thermal radiation, so this HEATS THE EARTH UP BITCHES

Question 15

why is the earths temperature rising ?

Answer 15

• population increase
• industrialisation = using more fossil fuels
• deforestation = less trees to lock up CO2
• more food produced so methane is released by cows
• ## more waste and landifll which is broken down by greenhouse gases

Question 16

what is the term for greenhouse gases being used more ?

Answer 16

global warming

Question 17

what do greenhouse gases do ?

Answer 17

insulate the earths atmosphere

Question 18

what does global warming cause ?

Answer 18

climate change

Question 19

what are the consequences of climate change ?

Answer 19

• ice caps melting = flooding = sea levels rising
• varied rainfall patterns = more/less rainfall in places - affects food production
• increased severity and frequency of storms
• temperature change affects availability of water so habitats are affected - difference in distribution

Question 20

what are human effects of climate change ?

Answer 20

• less crops, hunger
• coastal erosion

Question 21

why is climate change not accepted ?

Answer 21

biased
other factors

Question 22

what is a short term affect of climate change ?

Answer 22

blizzards

Question 23

what is a long term affect of climate change ?

Answer 23

sea levels rising

Question 24

what is a carbon footprint ?

Answer 24

a measure of the amount of carbon dioxide and other greenhouse gases used over the full life cycle of something

Question 25

what life cycles use carbon footprints ?

Answer 25

anything - events, humans, services

Question 26

what is a disadvantage of carbon footprints ?

Answer 26

difficult to measure as carbon is used all the time in everyday life

Question 27

how can we reduce carbon emissions ?

Answer 27

• renewable energy resources or nuclear energy used
• using less fossil fuels
• government putting up a tax when fossil fuels are used and only letting people with licenses make fossil fuels / capping how much is made
• technology called carbon capture and release captures the carbon dioxide produced by burning fossil fuels and stores it underground before it is released

Question 28

what are the problems with trying to reduce carbon footprints ?

Answer 28

• easier said than done, as it takes lots of work and technology
• governments worry taxing fossil fuels will hinder economic growth of communities, especially developing countries
• not everyone is willing to sacrifice money, profit
• it is hard to get people to change everyday lifestyle choices, e.g walking somewhere instead of driving as they are not educated or willing to change

Question 29

what happens in combustion ?

Answer 29

hydrocarbons are burnt, releasing carbon dioxide and water vapour if combustion is incomplete

Question 30

what is produced during incomplete combustion ?

Answer 30

carbon monoxide
soot
impurities, e.g sulfur - produces sulfur dioxide
oxides of nitrogen can be produced if the temp is too high nitrogen and oxygen reacts

Question 31

what is the issue with sulfer dioxide and nitrogen oxide ?

Answer 31

it causes respiritory problems

Question 32

what is the problem with incomplete combustion ?

Answer 32

particulates are inhaled which damages lungs, it is bad for the environment as it causes clouds which lets less light in for photosynthesis

Question 33

what is the problem with carbon monoxide ?

Answer 33

• it stops blood doing its job of carrying oxygen around the body which can cause fainting, comas

Question 34

what is acid rain the product of ?

Answer 34

sulfur dioxide and water in clouds forms sulfur and nitric acid

Question 35

what does acid rain do ?

Answer 35

damages building, statues
causes animals, plants and trees to die
causes human health problems with breathing