Topic 9 Content (P2)

Question 1

Stages in evolution of atmosphere

Answer 1

1. Volcanoes gave out gases
2. Oceans, algae + green plants absorbed CO2
3. Green plants + algae produced oxygen

Question 2

Atmosphere forming stage 1

Answer 2

Earth cooled enough to form crust
Volcanoes erupted releasing gases (N2, CO2, CH4, H2O) to make early atmosphere

Question 3

Atmosphere forming stage 2

Answer 3

Earth continued to cool
Water vapour condensed to form oceans
CO2 dissolved into oceans and reacted to form carbonate precipitates to form sediments on seabed (less CO2 in atmosphere)
Later marine animals evolved - shells/skeletons contained some carbonates from ocean
Green plants + algae evolved + absorbed some CO2 to carry out photosynthesis

Question 4

Atmosphere forming stage 3

Answer 4

Green plants and algae absorb CO2 from the atmosphere and produce oxygen by photosynthesis
Algae evolved first (2.7 billion years ago)
Then over the next billion years green plants evolved
As oxygen levels built up in the atmosphere, more complex life (animals) could evolve
200 million years ago the atmosphere reached a composition similar to today

Question 6

Todays atmosphere composition

Answer 6

78% nitrogen
21% oxygen
<1% other gases (eg carbon dioxide, noble gases + water vapour)

Question 7

Some carbon taking in from the atmosphere and oceans by organism became …..

Answer 7

Locked up in rocks and fossil fuels after the organisms died

Question 8

When plants, plankton and marine life die, they ….
Over millions of years they become …. And form …. (Trapping …. Within them and keeping it ….)

Answer 8

Fall to the seabed and get buried by layers of sediment
Compressed
Sedimentary rocks, oil and gas
Carbon
Out of the atmosphere

Question 9

Fossil fuel examples

Answer 9

Coal, crude oil + natural gas

Question 10

….. formed from deposits of plankton - form … under the seabed when trapped in rocks

Answer 10

Crude oil and natural gas
Resevoirs

Question 11

Coal is a ….. made from …..

Answer 11

Sedimentary rock
Thick plant deposits

Question 12

Limestone is a …. Made from …..

Answer 12

Sedimentary rock
Calcium carbonate deposits from shells and skeletons of marine organisms

Question 13

Greenhouse gases

Answer 13

Carbon dioxide
Water vapour
Methane

Question 14

Greenhouse gases act like an …… - this allows …..

Answer 14

Insulating layer in earth’s atmosphere
The Earth to be warm enough to support life

Question 15

Greenhouse gases don’t absorb ….. but they do absorb the ……. - then they …… causing warming of surface of Earth called ….

Answer 15

The incoming short wavelength radiation from the sun
Long wavelength radiation that gets reflected back off Earth
Re-radiate it in all directions (including back towards Earth)
Greenhouse effect

Question 16

Examples of human activity that increases amount of greenhouse gases in atmosphere 4x

Answer 16

Deforestation = fewer trees = less CO2 removed by photosynthesis
Burning fossil fuels = carbon locked up released as CO2
Agriculture = farm animals producing methane (digestion)
Creating waste = landfill sites + agricultural waste = more CO2 + methane released by waste decomposition

Question 17

Earths temp varies ….

Answer 17

Naturally

Question 18

Recently the earths average surface temp has been …..
the extra carbon dioxide is from …… causing this increase and leading to ….

Answer 18

Increasing by amounts that are greater than we would expect to see naturally
Human activity
Climate change

Question 19

Increase in temperature of earth leads to 4x

Answer 19

• polar ice caps melting - causing rise in sea levels, increased flooding in coastal areas and coastal erosion
• changes to rainfall patterns - too much or too little in regions - impact food production
• frequency and severity of storms increase
• affect wild species because of availability of water + temperature changing their distribution

Question 20

Carbon footprint is a measure of amount of ….

Answer 20

Carbon dioxide and other greenhouse gases released over the full life cycle of something

Question 21

Factors affecting carbon footprint:

Answer 21

Raw materials
Manufacture
Transport
Use
Disposal

Question 22

Reduce carbon footprint x5

Answer 22

• renewable energy sources or nuclear instead of fossil fuels
• efficient processes to conserve energy and cut waste (decomposes to release methane)
• gov. tax companies based on how much GG they emit - less polluting
• CO2 capture - produced by burning fossil fuels before released to be stored deep underground in cracks in rock such as old oil wells

Question 23

Lower CO2 emissions tech x2

Answer 23

• carbon capture and storage (developmental stage)
• renewable energy technologies (expensive) - more development would make then cheaper to be used more widely

Question 24

Individual reduce personal carbon footprint x3

Answer 24

• Choosing to cycle or walk instead of using car
• limiting air travel
• energy saving at home eg heating

Question 25

Due to incomplete combustion of hydrocarbons, …… are released and ….. can be produced as well as ….

Answer 25

particulates made up of soot and unburned hydrocarbons Carbon monoxide Carbon dioxide

Question 26

Particulate are bad because .. 2x

Answer 26

- if particulate inhaled, stuck in lungs + cause damage - lead to respiratory problems - bad for environment + reflect sunlight back into space so less light reaches earth causing global dimming

Question 27

Carbon monoxide problems x2

Answer 27

- binds to haemoglobin in blood so less oxygen is able to be transported around the body, can cause fainting, a coma or even death - no colour or smell so hard to detect - makes it more dangerous

Question 28

When …. Or …. Mix with water in the clouds they form …… or …… which then falls as ….. - kills …… and damages ….. - these gases can also cause …..

Answer 28

Sulfur dioxide or Nitrogen oxides Dilute sulfuric acid or Dilute nitric acid Acid rain Plants Buildings, statues + causes metal corrosion Respiratory problems