Topic 9: Chemistry of the atmosphere Flashcards
(26 cards)
what was earths early atmosphere like?
mostly carbon dioxide with virtually no oxygen
the early earth was mostly covered in?
volcanoes
how did oceans form?
the water vapor condensed to form oceans
why did the carbon dioxide levels go down?
- it was dissolved by the oceans to form carbon precipitates that formed sediments on the seabed
- plants used it for photosynthesis
how is coal formed?
from thick plant deposits
how is limestone formed?
calcium carbonate deposits from shells and skeletons
how is crude oil and natural gas formed?
from plankton
what is the formula for photosynthesis?
carbon dioxide + water –> glucose + oxygen
6CO2 + 6H2O –> C6H12O6 + 6O2
how does the enhanced greenhouse effects work?
the sun emits short wavelength radiation to earth which is not blocked by the earths greenhouse gases however the long wavelength radiation that is reflected back to space is blocked by greenhouse gases
what do humans do that increases greenhouse gases?
- Deforestation: less trees to remove CO2 through photosynthesis
- Burning fossil fuels: carbon is trapped in fossil fuels and is released when they are burned
- Agriculture: farm animals produce methane
- Creating waste: CO2 created by deposition of waste
why is our climate now changing?
because more CO2 is being released
what are the dangers of global warming?
1) ice caps melting: higher sea level causes flooding and more coastal erosion
2) changes in rainfall pattern causes places to get a surplus or reduced amount of rainfall
3) the frequency and severity of storms can increase
4) Changes in temperature and amount of water available in a habitat may affect wild species, leading to differences in their distribution
what are carbon footprints?
a measure of the amount of carbon dioxide and other gases released over the full life cycle of something
how can you reduce your carbon footprint?
- use renewable energy
- using efficient processes to conserve energy and cut waste
- governments could tax CO2 emissions
- there is technology that captures CO2
why is it hard to reduce CO2?
- technologies need to be developed
- hard to make international agreements of CO2
- people need to change their lifestyle
why do fossil fuels release CO2?
they contain hydrocarbons, during combustion the carbon and hydrogen in them is oxidised so carbon dioxide and water vapor is released into the atmosphere
what is complete combustion?
when there is a lot of oxygen so all the fuel burns
what is incomplete combustion?
when there is not enough oxygen for all the fuel to burn
what can incomplete combustion cause?
the release of carbon and carbon monoxide
what are the dangers of inhaling particles?
- particles stuck in the lungs can cause damage
- they are bad for the environment - they produce clouds
how/why is carbon monoxide dangerous?
- it stops your blood from doing its proper job carrying oxygen
- it does this by binding the haemoglobin in your blood that normally carries O2
- a lack of oxygen can cause fainting, a coma or even death
- carbon monoxide has no color and has no smell
how id sulphur dioxide released?
through the combustion of fossil fuels
how is nitrogen oxide released?
through the reaction between nitrogen and oxygen
what happens when nitrogen oxide or sulfur dioxide form clouds?
they form dilute sulfuric acid or dilute nitric acid which causes the cloud to have acid rain
