Earth and Atmosphere

Question 1

how do you measure the percentage of oxygen in the air

Answer 1

1. 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.
2. Repeat several times
3. As air pushed to and fro, the oxygen in the air reacts with the hot copper forming copper oxide
4. 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
5. repeat steps 1 and 2 until the volume of gas remains steady

Question 2

what is the test for hydrogen

Answer 2

test the gas with a lighted splint, a squeaky pop is heard

Question 3

what is the test for oxygen

Answer 3

test the gas with a glowing splint, the splint relights

Question 4

what is the test for carbon dioxide

Answer 4

bubble the gas into limewater, the limewater turns cloudy

Question 5

what are the elements present in the present atmosphere

Answer 5

78% nitrogen
21% oxygen
0.04% carbon dioxide
1% argon and other noble gases
water vapour

Question 6

what were the elements present in the early atmosphere

Answer 6

little or no oxygen
a large amount of carbon dioxide
water vapour
small amounts of other gases such as methane, ammonia and nitrogen

Question 7

how were the gases produced in the earth’s early atmosphere produced

Answer 7

by the large amounts of volcanic activity

Question 8

what did volcanoes release

Answer 8

carbon dioxide, water vapour and small amounts of other gases such as nitrogen

Question 9

why did the amount of water vapour in the atmosphere decrease

Answer 9

because the earth cooled and the water vapour condensed to liquid water forming the oceans

Question 10

why did carbon dioxide in the early atmosphere decrease

Answer 10

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

Question 11

why did oxygen in the atmosphere increase

Answer 11

oxygen was released by photosynthetic organisms, green algae and primitive plants during photosynthesis

Question 12

why did nitrogen in the atmosphere increase

Answer 12

there was an increase in nitrogen due to nitrogen accumulating because it is an unreactive gas that is released by volcanoes

Question 13

what are the green house gases

Answer 13

carbon dioxide, methane and water vapour

Question 14

describe how greenhouse gases warm up the earth

Answer 14

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

Question 15

what evidence supports the idea that carbon dioxide causes a rise in temperature

Answer 15

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.

Question 16

what human activities increase the carbon dioxide levels in the atmosphere

Answer 16

increased burning of fossil fuels in car engines and power stations

deforestation

Question 17

what human activities increase the methane levels in the atmosphere

Answer 17

livestock farming

finding and processing oil and natural gas

growing rice in paddy fields

putting waste in landfill sites

Question 18

what are the effects of climate change on the environment

Answer 18

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

Question 19

what are the effects of climate change on humans

Answer 19

food shortages in some regions
flooding of homes
more droughts
people may have to migrate from some affected areas
more extreme weather events

Question 20

effect of climate change on wildlife

Answer 20

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

Question 21

how can we lessen the effects of climate change

Answer 21

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

Question 22

how can we reduce greenhouse gas emissions

Answer 22

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

Question 23

what are some possible difficulties with reducing greenhouse emissions

Answer 23

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

Question 24

what are two ways of removing carbon dioxide from the atmosphere

Answer 24

capturing carbon dioxide from the air and burying it underground
planting many trees that take in carbon dioxide as they grow

Question 25

what are the difficulties with capturing carbon dioxide

Answer 25

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

Question 26

how can we adapt to new conditions

Answer 26

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