C6.3 - Earth Systems? 🌍

Question 1

describe the theory of how the atmosphere was originally formed

Answer 1

• intense volcanic activity released gases (like CO2 and H20) = formed early atmosphere
• earth cooled and water vapour condensed to form oceans
• left behind atmosphere of mainly carbon dioxide
• with small amounts of
  ammonia, methane
• little/no oxygen

Question 2

what kind of gases did the volcanoes release in the early atmosphere? (3 main, 2 non-main)

Answer 2

• huge volumes of water vapour
• carbon dioxide
• small amounts of nitrogen

and
- sulfur dioxide
- hydrogen sulfide

Question 3

how has an oxygen-rich atmosphere developed over time?

Answer 3

• plants and algae made their own food through photosynthesis
• took in carbon dioxide + water and released oxygen

Question 4

describe the four steps of the greenhouse effect

Answer 4

1) energy transferred by radiation from sun reaches earth’s surface
2) radiation warms up the earth’s surface
3) radiation emitted back into earth’s atmosphere
4) some is absorbed by greenhouse gases
5) others go directly into space

• this allows temperature to be regulated in the atmosphere

Question 5

what human activity increases levels of greenhouse gases in the atmosphere?

Answer 5

• driving (release CO2)

- raising cattle (methane)

Question 6

what are the uncertainties in past CO2 conc in air measurements? (2)

Answer 6

• Historical data is much less accurate due to the lack of accurate instrumentation and methods
• Fewer locations would also have been measured due to the lack of satellites and transport

Question 7

potential effects of increased levels of carbon dioxide + methane on earth’s climate

Answer 7

• increase in average global temperatures
• extinction of species
• raised sea levels

Question 8

how can greenhouse gas emissions be reduced?

Answer 8

• reduce consumption of fossil fuels BIOFUELS
• renewable energy resources
• using CARBON CAPTURE (prevent carbon dioxide from escaping)

Question 9

main source of carbon monoxide?

Answer 9

• incomplete combustion of fuels with carbon

- ie. in vehicle engines

Question 10

problem with increased amount of carbon monoxide? (and why)

Answer 10

• is a toxic gas
• has no colour, taste smell
• reduces amount of oxygen bloodstream can carry by binding w/ haemoglobin
• causes drowsiness/difficulty breathing/death

Question 11

main source of sulfur dioxide

Answer 11

• burnt fossil fuels

they contain small amounts of sulfur compounds

Question 12

problems of increased amount of sulfur dioxide?

Answer 12

• causes acid rain

- breathing difficulties

Question 13

what are the products of complete combustion of fossil fuels? (4)

Answer 13

• oxides of nitrogen
• carbon dioxide
• oxides of sulfur
• water vapour

Question 14

problem with increased amount of oxides with nitrogen?

Answer 14

• acid rain
• asthma

Question 15

what does acid rain do to stone, metal, trees and living things

Answer 15

• erodes stonework, corrodes metal
• kill trees
• kill living things in rivers/lakes

Question 16

main source of particulates in atmosphere?

Answer 16

• produced in industrial processes like metal extraction
• incomplete combustion of fossil fuels
• in vehicle engines

Question 17

what are particulates?

Answer 17

microscopic particles of solid or liquid matter suspended in the air

Question 18

problem caused by increased amount of particulates in the atmosphere

Answer 18

• global dimming
• small particles settle in lungs
• breathing problems (bronchitis, increase chance of heart disease)

Question 19

where does tap water come from?

Answer 19

• water stored in lakes/reservoirs
• or in aquifiers
• from lakes/waste water

Question 20

what are the 5 steps which describe how fresh water is treatd?

Answer 20

1) passes through screen (metal bars which trap large things like leaves + twigs)
2) passes through settlement tank (where soil + sand settle out)
3) aluminium sulfate + lime added (causes small particles of dirt to clump together + sink to bottom)-SLUDGE
4) water passed through fine sand filter (removes mud/grit)
5) chlorine added to kill bactera
6) pH checked + neutralised

Question 21

what is groundwater?

Answer 21

water found underground in cracks/spaces in soil/sand/rock

Question 22

where is groundwater stored (and where and how does it move)?

Answer 22

• stored in geological formations of soil, sand, rock

- moves slowly through aqufiers

Question 23

where is salt water found?

Answer 23

sea water

Question 24

what is the name of the processes used to treat salt water? (and large scale or small scale) (2)

Answer 24

• simple distillation for large scale
• reverse osmosis for small scale
• both are desalination processes

Question 25

what factors would affect whether desalination would be worthwhile in a country? (2)
(and give an example where they use it)

Answer 25

• where freshwater supply is low
• cost of energy resources is low
• ie. coast on middle east

Question 26

what characteristics must water have to make it potable? (3)

Answer 26

• Have a pH between 6.5 and 8.5.
• The dissolved substances (e.g. salts) will be present is very small regulated quantities
• Be free of bacteria or potentially harmful microbes

Question 27

what does it mean if water is potable?

Answer 27

safe to drink

Question 28

extra products of incomplete combustion of fossil fuels (in comparison w/ complete combustion) (2)

Answer 28

• carbon, which clubs together forming carbon particulates
• carbon monoxide