CHAPTER 11 - THE EARTHS ATMOSPHERE Flashcards
What is the proportion of earths atmosphere (5 gases most to least)
Nitrogen(N2) - 78%
Oxygen(O2) - 21%
Argon(Ar) - 0.9%
Carbon dioxide(CO2) - 0.004%
Water vapour and group 0 - traces
How did earths early atmosphere form
Due to intense volcanic activity releasing gases
Why has oxygen levels increased since the early atmosphere
They increased due to algae and plants evolving, and to survive they photosynthesised so took in lots of carbon dioxide and give out oxygen. So due to this carbon levels dropped and oxygen levels increased ( to show this use the photosynthesis equation carbon dioxide + water ——> oxygen + glucose)
What 5 gases made up earths early atmosphere
Carbon dioxide(CO2)
Water vapour(H2O)
Nitrogen(N2)
Ammonia(NH3)
Methane(CH4)
Why has CO2 levels drastically decreased since earths early atmosphere
Firstly due to abundant revolution of algae and green plants where they photosynthesised a lot and took out lots of CO2 from the atmosphere. But also as the oceans formed the CO2 dissolved into the oceans being absorbed by marine life. Which formed into sedimentary rocks but overall which it removed it from the atmosphere
How has sedimentary rock formed from Co2 in the atmosphere
Sedimentary rock: it dissolves inn the ocean and can form insoluble compounds which falls to the ocean floor as sediment, forming the rock. Or it forms soluble compounds which marine life take in then which forms shells and skeletons which falls to ocean floor as sediment,forming the rock
How has oil and gas, and coal formed from CO2 in the atmosphere
Oil and gas: CO2 is used in photosynthesis in plankton and algae in the oceans which decays under heat and pressure forming crude oil and natural gas.
Coal:CO2 used un photosynthesis goes to plants in swamps which decays under heat pressure forming coal
What do greenhouse gases do in the atmosphere
Maintain temperatures on earth high enough to support life.
Steps of the greenhouse effect(4)
1.-short wave radiation such as UV and visible radiation is emitted from the sun.
2.-the earth absorbs most radiation and warms up, it cools and reflects lower energy infrared radiation which is long wave
3.-some emitted heat radiation passes through the atmosphere into space
4.-the greenhouse gases absorb most of the reflected infrared radiation and re-radiate it warming up the atmosphere
What human activities increase the amount of carbon dioxide and methane
CO2-burning fossil fuels, deforestation higher temps resulting less co2 dissolving in the ocean
CH4-paddy fields, production of f beef/milk, decay of landfill by microorganisms
What are 4 consequences of global climate change
1.-rising sea levels
2.-extreme weather events
3. Change in temperatures and distribution of rainfall
4.-changes to distribution of wildlife species
Why is there an problem in understanding of climate change in the future
As it’s very complex and difficult to model
3 different greenhouse gases their formula and description
Water vapour (H2O) - produced from power stations or evaporation of oceans, seas, rivers, and lakes
Sulfur dioxide(SO2) - pollution from combustion of fuels in power plants or vehicles
Nitrous oxide (N3O) - produced from combustion engines of vehicles, agriculture or through the nitrogen cycle
What is the carbon footprint
The total amount of CO2 and other greenhouse gases emitted over the full life cycle of a product, service event
2 ways you can limit CO2 and CH4
CO2: improve home insulation to conserve energy limiting greenhouse gas use and can tax cars what burn lots of fossil fuels
CH4: send less waste to landfill by recycling more and have plant based diets which limits cattle farming
3 things a person can do to reduce their carbon footprint
- Use less heating
- Eat less meat
- Use more public transport
How is carbon dioxide and monoxide and soot formed, the problems and solutions
CO2:produced when fossil fuels burn in plenty of air(combustion). It’s the main greenhouse gas contributing to climate change however changing the conditions hydrocarbons are burnt can change the products made
CO:when not enough oxygen in an engine incomplete combustion occurs which produces carbon monoxide. It’s a toxic colourless gas which can poison you leading to death. Instead you can use electric cars
C(soot): large molecules in diesel engines react with oxygen and don’t completely burn leading to tiny solid particles containing carbon and unburnt hydrocarbons are produces. It causes global dimming and may damage cells in our lungs potentially leading to cancer, in-turn you can use electric cars or non diesal cars.
How is sulfur dioxide,nitrogen oxide and unburned fuels formed, the problems and solutions
sulfur dioxide(SO2) - when oxygen reacts with fossil fuels when burned. It’s toxic and can cause acid rain. However sulfur impurities can be removed from a fuel before burnt or react with basic calcium oxide for neutralisation.
nitrogen oxides(NO/NO2) - High temps in engine allow nitrogen to react with oxygen. It’s toxic and can cause acid rain and trigger peoples asthma. Instead use electric cars
Unburned fuels - forms when part of the fuels escape combustion. It causes lung damage but Changing the conditions hydrocarbons are burnt can change products made
