Recycling of Metals

Which of the following is not a reason for recycling metals?

• Metal ores are a finite resource.

• Recycling metals increases the purity of the metals.

• Recycling reduces the cost of producing the metals.

• Recycling reduces the pollution of the atmosphere.

Which of these statements describe a reason for recycling metals?

      1          Alloys contain a mixture of metals.

      2          Metal ores are a finite resource.

      3          Landfill rubbish sites are a source of pollution.

• 1 only

• 3 only

• 1 and 3

• 2 and 3

Over 90% of all gold but less than 50% of iron is recycled.

What is the reason for this difference?

• Gold is very scarce.

• Iron does not cause land pollution.

• Iron ores will never run out.

• It is more expensive to purify gold.

Which statements about the reasons for recycling metals are correct?

1          It is cheaper to recycle metals than extract them from their ores.

2          The demand for metals is always increasing.

3          Recycling metals requires more energy than the extraction of metals from their ores.

4          There is only a limited supply of metal ores.

• 1 only

• 1 and 2 only

• 1, 2 and 4 only

• 1, 3 and 4 only

Supplies of metal ores are finite.

Recycling helps us to make reserves of metals last longer.

Which way shows how metals are recycled to give a pure metal?

• impure metal --> melted --> pure metal

• metal ore --> melted --> pure metal

• objects of different metals --> crushed --> melted --> pure metal

• objects of same metal --> crushed --> melted --> pure metal

As the demand for metals increases, the need for recycling increases.

Which row shows the type of resource that metals are an advantage of recycling them?

• type of resource : finite

  advantage : a large amount of waste material is produced during recycling

• type of resource : finite

  advantage : saves energy and costs compared to extracting new metals from their ores

• type of resource : infinite

  advantage : a large amount of waste material is produced during recycling

• type of resource : infinite

  advantage : saves energy and costs compared to extracting new metals from their ores

In 2013, 97% of all Singapore's iron waste and 84% of other metal waste was recycled.

On economic grounds, which statement supports recycling on such a large scale?

• It increases the cost of transport of waste to recycling sites.

• It prevents unsightly waste metal left in the environment.

• It reduces the amount of air pollution when melting metal waste.

• It saves money and natural resources.

Which statement about the recycling of metals is correct?

• Metal ores are a renewable resource.

• Recycling conserves the resources of metal ores.

• Recycling metals increases the amount of waste at landfill sites.

• Recycling metals always uses more energy than mining and extracting the metal from the ore.

Most aluminium cans are made from recycled aluminium.

Why are some aluminium cans still made from aluminium extracted from its ore?

• Aluminum ore produces better quality aluminium.

• Demand is not met by the recycling of aluminium alone.

• Extraction from the ore uses electricity and is expensive.

• There are only a limited number of times that aluminium can be recycled.

Which is not a reason for recycling copper?

• Copper made by recycling is less pure than that made by extraction

• Less energy is needed in recycling than extraction

• To conserve copper ore

• To reduce damage to the environment by mining