C14 - The Earth's Resources 2️⃣✅

Question 1

What is a finite resource?

Answer 1

Resources that are being used up faster than they can be replaced.

Question 2

What is a renewable resource?

Answer 2

Resources that be renewed at the same rate at which they are used up

Question 3

Give 2 examples of finite resources which are processed to either give energy or materials

Answer 3

ENERGY: crude oil processed to produce fuel for multiple different methods of transport
MATERIALS: crude oil is processed to produced plastics for clothing or sheets

Question 4

Give 2 examples of renewable resources which humans supplement by agriculture

Answer 4

• wood/ timber
• clothing/ leather/ cows

Question 5

Give 2 examples of synthetic products which can be used instead of natural resources?

Answer 5

• Cotton - clothing —> polyester
• wood - material —> PVC

Question 6

What are synthetic products and why are they used instead of natural rescources?

Answer 6

Synthetic products are when it is not made up of natural substances, like cotton or wool, and is man-made artificially from chemical reactions

Question 7

What is potable water?

Answer 7

Water that is safe to drink with low levels of dissolved salts and microbes

Question 8

What is pure water?

Answer 8

That is pure H20, just one molocule, no other substances in it

Question 9

Why is potable water not pure water?

Answer 9

Because, even though it contains low levels, it still contains levels of dissolved substances, so its not 100% H20

Question 10

How can we collect fresh water in the uk?

Answer 10

rainwater contains low levels or dissolved substances and can be found and obtained underground, in lakes or in rivers

Question 11

How do we produce potable water in the uk?

Answer 11

1. sedimentation - solids in water sink to bottom of tank and are removed
2. filtration - fine particles like sand are removed via filterbeds
3. sterilisation - mircobes left in water are killed using sterilisng agents

Question 12

What 3 sterilising agents are used in the treatment of fresh water?

Answer 12

• Chlorine
• Ozone
• Ultraviolet (UV) light

Question 13

What is the best sterilising angent and why?

Answer 13

UV light is the best as it leaves nothing in the water after its used whereas ozone and chlorine still leave small ammounts in the water

Question 14

What are 2 alternate methods of obtaining potable water if large ammounts of fresh water arent avainable?

Answer 14

• Disitllation
• Reverse Osmosis

Question 15

How do you obtain potable water without fresh water?

Answer 15

Desalination of sea water

Question 16

How does distillation work?

Answer 16

By a liquid (sea water) being heated to boiling point in order to vaporize it, then condensed back into a liquid so that it is separated from impurities (e.g. salt)

Question 17

How does reverse osmosis work?

Answer 17

Where seawater is forced through a membrane at high pressure. The membrane allows water molecules to pass through but prevents any other chemicals dissolved in the water from passing through

Question 18

What is a negative to desanlination?

Answer 18

Both methods are very expensive and require lots of energy

Question 19

What are the 4 steps to treating waste water?

Answer 19

1. Screening and grit removal
2. Sedimentation
3. Anaerobic digestion of sewage sludge
4. Aerobic biological treatment of effluent (liquid waste)

Question 20

(Treating waste water)

How does screening work?

Answer 20

Large solid particles are removed (e.g. grit) by passing the sewage through a fine screen

Question 21

(Treating waste water)

How does sedimentation work?

Answer 21

Sedimentation allows the smaller solid particles (sediment) to settle at the bottom of the tank forming sewage sludge while the liquid effluent remains above

Question 22

(Treating waste water)

How does Anaerobic digestion of sewagte sludge work?

Answer 22

The sewage sludge is dried and anerobically digested (broken down by microorganisms in the absence of oxygen) therefore removing organic matter amd also producing biogas for electricity

Question 23

(Treating waste water)

How does aerobic biologucal treatment of effluent work?

Answer 23

The effluent is aerobically digested (broken down by microorganisms in the presence of oxygen). Removing any remaining organic matter and harmful microbes

Question 24

How is it ensured that effluent is rid of any remaining organic matter or harmful microbes?

Answer 24

Lots of 02 is bubbled into the water to make sure its digested aerobically (with oxygen)

Question 25

What are the 3 main methods to obtain potable water?

Answer 25

• Treatment of fresh water
• Desalination of salty/ sea water
• Treatment of waste water

Question 26

Rank the 3 main methods for obtaining potable water from best to worst

Answer 26

1. Treatment of fresh water - requires little to no energy and minimal equipment
2. Treatment of waste water - requires more equipment but less energy
3. Desalination - requires lots of energy and specialist equipment

Question 27

What are Life Cycle Assessments (LCAs)?

Answer 27

An assessment carried out to assess the environmental impact of prodcuts at each stage of its ‘life’

Question 28

What are the 5 things assessed in a LCA?

Answer 28

1. Extrating and processing of raw materials
2. Manufacturing and packaging
3. Use and if it can be reused
4. Disposal and the end of its useful life
5. Transportation and distributuion at each stage

Question 29

What metals can be extracted by the reduction of carbon?

Answer 29

• Zinc
• Iron
• Copper

Question 30

How is carbon displacement/ reduction used to extract metals?

Answer 30

Carbon atoms displace the metals and take the oxygen from the metal oxide to form carbon dioxide, leaving behind a pure metal

Question 31

Why can we only extract zinc, iron and copper using carbon?

Answer 31

Because they are less reactive than carbon so it will displace them

Question 32

What metals can be extracted using electrolysis?

Answer 32

• Potassium
• Sodium
• Lithium
• Calcium
• Magnesium

Question 33

What is phytomining?

Answer 33

Using plants to absorb and therefore extract metal compounds

Question 34

How does phytomining work?

Answer 34

1. Plants are grown on a low-grade ore
2. Plants absorb the metal ions through there roots
3. Plants are then harvested and burnt
4. The ash left behind contains a higher concetration of metal than the original ore
5. Ash is then processed to obtain the metal

Question 35

What is bioleaching?

Answer 35

Using bacteria to produce leachate solutions that contain metal compounds

Question 36

How does bioleaching work?

Answer 36

Certain bacteria can break down low-grade ores to produce an acidic solution containing copper ions. This solution is called a leachate and can be separated using electrolysis or displacement reactions to form a pure metal.

Question 37

What are 2 biological methods of metal extraction?

Answer 37

Bioleaching & Phytomining

Question 38

What is the positive and negatives to phytomining?

Answer 38

• Its slow
• requires high temperatures
• But conserves supplies of finite ores
• Reduces rock waste that has to be disposed of

Question 39

What is the positive and negatives to bioleaching?

Answer 39

• doesnt require high temperatures
• But produces toxic substances including sulfuric acid which can damage the environment

Question 40

What is an ore?

Answer 40

Ores are naturally occurring rocks that contain metals or metal compounds

Question 41

What is desalination?

Answer 41

Desalination is the process by which the dissolved mineral salts in water are removed