the earth's resources (required practical)

Question 1

what is a natural resource?

Answer 1

a resource that forms without human input. (things that come from the earth basically)

Question 2

what are finite resources?

Answer 2

resources that aren’t formed quick enough to be replaceable.

Question 3

what are the problems with extracting finite resources?

Answer 3

uses lots of energy.
scars land.
produces waste.

Question 4

what is sustainable development?

Answer 4

development that thinks about future generations aswell as present ones.

Question 5

why is it important to recycle metals?

Answer 5

mining metals takes a lot of energy but recycling uses less.
reduces waste sent to landfill.

Question 6

why is it important to recycle glass?

Answer 6

reduces the amount of energy need for new glass.

Question 7

what does a life cycle assessment look at? (4)

Answer 7

a life cycle assessment shows the total environmental cost of something.
1. getting raw materials - extracting materials damages the environment and releases pollution, processing materials uses lots of energy.
2. manufacture and packaging - manufacturing uses lots of energy and waste products need to be disposed.
3. using the product - how long a product is used for or how many uses it gets means less waste in the long run.
4. product disposal - energy is used to transport waste to landfill which pollutes land and water and uses space.

Question 8

what are the problems with life cycle assessments?

Answer 8

it is hard to give a number value to some pollutants.
some assessments can ignore impacts to support the claims of a company.

Question 9

what is potable water?

Answer 9

water you can drink.

Question 10

how can water be purified and tested? (practical)

Answer 10

1. test the pH of your water with a pH meter. (if the pH is too high or low it can be neutralised with a titration)
2. test the water for sodium chloride (salt) with a flame test for sodium and nitric acid + silver nitrate for chloride.
3. distil the water with a distillation apparatus.
4. retest the water for sodium chloride and the pH.

Question 11

where does waste water come from?

Answer 11

agricultural systems.
sewage from domestic sources. (like a bath)
industrial processes.

Question 12

how is sewage treated?

Answer 12

1. before treatment sewage is screened which removes large bits of material.
2. sedimentation causes heavy solid to sink and form a sludge at the bottom of a settlement tank.
3. the lighter material is removed and treated with biological aerobic digestion. (air is pumped through the water to get aerobic bacteria to break down organic matter)
4. for the heavy solids anaerobic digestion breaks down organic matter in the sludge releasing methane gas. (which can be used as an energy source)
5. remaining digested waste can be used as fertiliser.
6. for waste with toxic substances chemicals may be added or UV radiation is used.