A factory makes steel shelf brackets. The steel is made from iron ore and no recycled steel is used. The brackets are redesigned so that 20% less steel is needed to make the same number of brackets. The steel is made by the same process as before.
Which conclusion about the iron ore needed to make the brackets is correct?
The mass of iron ore needed decreases by 80%.
The mass of iron ore needed decreases by 20%.
The mass of iron ore needed decreases only if recycled steel is used.
The mass of iron ore needed is unchanged because the same number of brackets is made.
99 exam-style questions on AQA GCSE Chemistry 10.2 Life cycle assessment and recycling, covering 10.2.1 Life cycle assessment and 10.2.2 Ways of reducing the use of resources. Each one has a worked solution and a mark scheme showing where the marks go.