The table shows the energy needed to produce 1 tonne of two metals.
| Metal | Energy to produce 1 tonne from ore in GJ | Energy to produce 1 tonne by recycling in GJ |
|---|---|---|
| aluminium | 200 | 10 |
| steel | 20 | 8 |
Which conclusion is correct?
Recycling steel saves 40% of the energy needed to produce steel from ore
Recycling aluminium uses 5% of the energy needed to produce it from ore
Recycling saves a greater percentage of the energy for steel than for aluminium
Recycling 1 tonne of aluminium saves 20 times the energy saved for 1 tonne of steel
45 exam-style questions on Edexcel GCSE Chemistry 5.1 Obtaining and using metals, covering 5.1.1 The reactivity series of metals, 5.1.2 Displacement reactions as redox reactions, 5.1.3 Extracting metals from ores by reduction, 5.1.4 Biological methods of metal extraction, 5.1.5 Resistance to oxidation and recycling metals, and 5.1.6 Life cycle assessment. Each one has a worked solution and a mark scheme showing where the marks go.