Chapter 14 - The Earth Resources

Question 1

Define ‘finite resources’

Answer 1

• Resources being used up at a faster rate than they can be replaced
• This means they will eventually run out being used at the current rate
• E.g fossil fuels

Question 2

Define ‘renewable resources’

Answer 2

• Those that can be replaced at the same rate at which they are used up
• Crops to make biofuels

Question 3

Example of a natural product and its use

Answer 3

• wool
• to make carpets, clothes

Question 4

Example of agricutural product and its use

Answer 4

• cotton
• clothes, textiles

Question 5

Example of a synthetic product, what it replaces and its use

Answer 5

• Nylon
• Replaces silk in clothes

Question 6

2 examples of natural resources as raw materials to make new products

Answer 6

• Metal ores used to extract metals
• Limestone to make cement and concrete

Question 7

Why are some predictions of finite resource usage not valid?

Answer 7

• They don’t build in the effect of recycling

Question 8

Why are industries turning to renewable resources?

Answer 8

• Conserve finite resources
• Improve sustainability

Question 9

Example of renawable resource?

Answer 9

• Polymers in the plastic industry
• Many use ethene made from ethanol
• Made by fermenting glucose from sugar cane or sugar beet
• More sustainable

Question 10

What is the difference between potable and pure water?

Answer 10

• Potable is water that is fit to drink; which still can contain impurities or added minerals
• Pure water is drinkable; but doesn’t contain impurities or added minerals

Question 11

Describe the process of treating ground water

Answer 11

• Water passes through a screen made of bars of metal. Catches large objects such as leaves and twigs
• Goes into a settlement tank; sand and soil out
• Aluminium Sulfate is added. Dirt clumps and forms sludge, dumped in landfill.
• Passed through sand and gravel. Removes mud or grit. Water is clean
• Chlorine added to remove bacteria. pH is checked and corrected

Question 12

How is salt water purified?

Answer 12

Distillation, called desalination

Question 13

What are the disadvantages and advantages of desalinating salt water

Answer 13

• Dis : Expensive
• Adv : Large Supply

Question 14

Why is a shortage of water a problem for some hot countries even though they have coastlines?

Answer 14

No natural sources of water

Question 15

Name another process besides distillation to purify salt water

Answer 15

Reverse osmosis

Question 16

Describe how waste water is made safe to release into the enviornment

Answer 16

• Screening : Removes large objects and grit
• Primary Treatment : Solid sediment (sludge) leaves the mixture, as large paddles rotate and it is kept in a storage tank
• Secondary Treatment : Bacteria feed on harmful bacteria and microorganisms, breaking them down anerobically. Can take several hours/days
• Final treatment : Bacteria leaves the water. Chlorine sometimes used to sterlise. It is now safe to release into rivers/sea

Question 17

Outline a concern of realeasing waste water into rivers

Answer 17

• Release of chlorine into rivers (which is added as a sterliser) is a concern
• Toxic organic compounds of chlorine can be formed

Question 18

State two uses of sewage sludge

Answer 18

• Used as fertiliser on farmland
• Source of renewable energy

Question 19

Describe a process used to treat sewage sludge

Answer 19

• Digested anerobically by micro organisms beneath the surface of a treatment tank
• Carried out at 35-55 degrees, higher temp is faster but requires more energy to heat
• Breakdown products include biogas, which can be burned to provide electricity.
• Sludge used as fertiliser or as a source of renewable energy

Question 20

Suggest a method for testing the purity of salt water