Alloys

Why can gold be found in the Earth's crust in its native state?

• Gold is very rare.

• Gold is very unreactive.

• Gold is more reactive than silver.

Why is aluminium extracted from aluminium ore by electrolysis?

• Aluminium is more reactive than carbon.

• Aluminium is less reactive than carbon.

• Aluminium is an expensive metal.

Why is iron extracted from iron ore by reduction with carbon or carbon monoxide?

• Iron is more reactive than carbon.

• Iron is less reactive than carbon.

• Iron is a cheap metal.

What happens to iron oxide in a blast furnace?

• It is oxidised to form iron.

• It is electrolysed to form iron.

• It is reduced to form iron.

In comparison with steel, what is pure iron like?

• Harder

• More magnetic

• Softer

• More resistant to rusting

What is the percentage of iron from the iron in the blast furnace?

• 100%

• 96%

• 4%

Which type of steel is likely to be used for making cutlery?

• Low carbon steel

• High carbon steel

• Stainless steel

What process is used to purify copper?

• Electrolysis

• Filtration

• Reduction in a blast furnace

• Phytomining

Why is titanium expensive to extract from its ore?

• It resists corrosion

• Several stages are involved

• Its ore is rare

Phytomining involves...

• Using plants to absorb metal compounds

• using bacteria to absorb metal compounds

• using chemicals to absorb metal compounds