Science - Chemistry - Chemistry of the Atmosphere - C9 Flashcards
what are the 2 main gases in the atmosphere ?
nitrogen
oxygen
what percentage of the atmosphere is nitrogen ?
roughly 80%
what percentage of the atmosphere is oxygen ?
roughly 20%
what was earth like at the beginning ?
molten, so hot that atmosphere dispersed into space
give a timeline of earths atmosphere forming
- 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
why is the earths atmosphere timeline not 100% definate ?
no scientists were there at the time
how was carbon dioxide removed from the atmosphere ?
- absorption from atmosphere
-absorption of green plants and algae - locking away carbon dioxide
how was carbon dioxide absorbed from the atmosphere ?
- 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
how was carbon dioxide absorbed by green plants and algae ?
by photosynthesis
how was carbon locked up ?
- 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
how did the volume of oxygen in the atmosphere increase ?
- produced by photosynthesis
- as oxygen built up, more complex life evolved
how is there evidence for the evolution of the atmosphere ?
- 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
give examples of greenhouse gases ?
methane
carbon dioxide
water vapour
what is the greenhouse effect ?
- 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
why is the earths temperature rising ?
- 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
what is the term for greenhouse gases being used more ?
global warming
what do greenhouse gases do ?
insulate the earths atmosphere
what does global warming cause ?
climate change
what are the consequences of climate change ?
- 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
what are human effects of climate change ?
- less crops, hunger
- coastal erosion
why is climate change not accepted ?
biased
other factors
what is a short term affect of climate change ?
blizzards
what is a long term affect of climate change ?
sea levels rising
what is a carbon footprint ?
a measure of the amount of carbon dioxide and other greenhouse gases used over the full life cycle of something
what life cycles use carbon footprints ?
anything - events, humans, services
what is a disadvantage of carbon footprints ?
difficult to measure as carbon is used all the time in everyday life
how can we reduce carbon emissions ?
- 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
what are the problems with trying to reduce carbon footprints ?
- 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
what happens in combustion ?
hydrocarbons are burnt, releasing carbon dioxide and water vapour if combustion is incomplete
what is produced during incomplete combustion ?
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
what is the issue with sulfer dioxide and nitrogen oxide ?
it causes respiritory problems
what is the problem with incomplete combustion ?
particulates are inhaled which damages lungs, it is bad for the environment as it causes clouds which lets less light in for photosynthesis
what is the problem with carbon monoxide ?
- it stops blood doing its job of carrying oxygen around the body which can cause fainting, comas
what is acid rain the product of ?
sulfur dioxide and water in clouds forms sulfur and nitric acid
what does acid rain do ?
damages building, statues
causes animals, plants and trees to die
causes human health problems with breathing
