Earth and Atmosphere Flashcards
how do you measure the percentage of oxygen in the air
- Heat the tube containing copper using a bunsen burner. Then push in the plunger of syringe A and this forces the air into B. When A is empty, push in the plunger of syringe B and this forces the air back into A.
- Repeat several times
- As air pushed to and fro, the oxygen in the air reacts with the hot copper forming copper oxide
- Stop heating the tube after about 3 minutes and allow the apparatus to cool. Then push all the has into one syringe and measure its volume
- repeat steps 1 and 2 until the volume of gas remains steady
what is the test for hydrogen
test the gas with a lighted splint, a squeaky pop is heard
what is the test for oxygen
test the gas with a glowing splint, the splint relights
what is the test for carbon dioxide
bubble the gas into limewater, the limewater turns cloudy
what are the elements present in the present atmosphere
78% nitrogen
21% oxygen
0.04% carbon dioxide
1% argon and other noble gases
water vapour
what were the elements present in the early atmosphere
little or no oxygen
a large amount of carbon dioxide
water vapour
small amounts of other gases such as methane, ammonia and nitrogen
how were the gases produced in the earth’s early atmosphere produced
by the large amounts of volcanic activity
what did volcanoes release
carbon dioxide, water vapour and small amounts of other gases such as nitrogen
why did the amount of water vapour in the atmosphere decrease
because the earth cooled and the water vapour condensed to liquid water forming the oceans
why did carbon dioxide in the early atmosphere decrease
green algae and primitive plants used carbon dioxide for photosynthesis
some carbon dioxide dissolved in the oceans so there was less in the atmosphere
some carbon dioxide became locked up in fossil fuels such as coal
why did oxygen in the atmosphere increase
oxygen was released by photosynthetic organisms, green algae and primitive plants during photosynthesis
why did nitrogen in the atmosphere increase
there was an increase in nitrogen due to nitrogen accumulating because it is an unreactive gas that is released by volcanoes
what are the green house gases
carbon dioxide, methane and water vapour
describe how greenhouse gases warm up the earth
energy from the sun is transferred to the Earth in the form of high energy radiation
some of this energy is absorbed by the earth’s surface, warming it up
the warm earth emits energy as infrared radiation
the greenhouse gases absorb some energy radiated from the earth
when the gases re emit the energy, some of it is transferred back to the earths surface
what evidence supports the idea that carbon dioxide causes a rise in temperature
experiments done in the lab show that carbon dioxide can absorb infrared waves and their energy.
Information from satellites show that as carbon dioxide levels in the atmosphere have increased, the amount of infrared waves leaving the Earth’s atmosphere have decreased.
what human activities increase the carbon dioxide levels in the atmosphere
increased burning of fossil fuels in car engines and power stations
deforestation
what human activities increase the methane levels in the atmosphere
livestock farming
finding and processing oil and natural gas
growing rice in paddy fields
putting waste in landfill sites
what are the effects of climate change on the environment
melting of ice caps and glaciers
rise in sea levels which could lead to coastal flooding
changing weather patterns, including more storms and heavy rainfall
desertification in some regions
what are the effects of climate change on humans
food shortages in some regions
flooding of homes
more droughts
people may have to migrate from some affected areas
more extreme weather events
effect of climate change on wildlife
animals may have to move to different areas in search of food
some species of plant and animals could become extinct
destruction of natural habitats as a result of extreme weather patterns
high temperatures will bleach coral and kill it
how can we lessen the effects of climate change
reducing the amount of greenhouse gases we add to the atmosphere
removing carbon dioxide from the atmosphere
helping people adapt to the changes in weather conditions
how can we reduce greenhouse gas emissions
using renewable sources of energy that do not produce carbon dioxide
capping landfill sites and using the methane to generate electricity
capturing the carbon dioxide emitted by power stations and burying it underground
what are some possible difficulties with reducing greenhouse emissions
some countries may not help and so the effect wont get as significant
we would still be adding greenhouse gasses to the atmosphere, just not as fast as before
it may not be enough to reduce the effects of climate change
some ecosystems may be disrupted
what are two ways of removing carbon dioxide from the atmosphere
capturing carbon dioxide from the air and burying it underground
planting many trees that take in carbon dioxide as they grow
what are the difficulties with capturing carbon dioxide
cost is very high
complexities of international agreement
being able to model the impact on Earth
difficult to find suitabel places to store carbon dioxide
how can we adapt to new conditions
building flood defences such as sea walls, sand dunes and barriers along rivers
building dams at river mouths to manage water supply
developing new strains of crops that will grow in different conditions
