Why can gold be found uncombined in the Earth's crust?
Gold is very rare
Gold is very unreactive
Gold is more reactive than silver
Why is iron extracted from iron ore by heating with carbon?
Iron is more reactive than carbon
Iron is less reactive than carbon
Iron is a cheap metal
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
What process is used to purify copper?
Electrolysis
Filtration
Reduction in a blast furnace
What is aluminium oxide dissolved in so that electrolysis can be carried out?
Distilled water
A concentrated solution of ethanol
Cryolite
Which of the following is a disadvantage of recycling metals?
Metal ores are conserved
Less energy is needed compared to producing metals from metal ores
Used metal items must be collected and sorted
What is the main purpose of a life-cycle assessment?
To analyse the environmental impact of a product when manufacturing it
To analyse the environmental impact of a product from obtaining raw materials to final disposal
To analyse the environmental impact of a product when using and maintaining it
What is produced at the cathode during the electrolysis of aluminium oxide?
Aluminium
Oxygen
Carbon dioxide
What does phytoextraction involve? - Higher
Using plants to absorb metal ions
Using bacteria to absorb metal ions
Using non-metal compounds to absorb metal ions
Copper can be obtained by reacting solutions of copper compounds with scrap iron. What is this sort of reaction called? - Higher
Neutralisation
Combustion
Displacement