A coastal village has little rainfall but a large supply of seawater. Sand filtration removes suspended particles but leaves dissolved salts in the water.
Which treatment would remove the salts to provide drinking water?
Filter the seawater, then add chlorine to the filtrate.
Warm the seawater, then return all vapour to the seawater.
Evaporate the seawater, then collect and condense the vapour.
Settle the seawater, then pour off the liquid above the sediment.
44 exam-style questions on Edexcel GCSE Biology 9.3 Material cycles and decomposition, covering 9.3.1 Cycling of materials through ecosystems, 9.3.2 The carbon cycle, 9.3.3 The water cycle, 9.3.4 The nitrogen cycle, 9.3.5 Indicator species and pollution, 9.3.6 Decomposition in preservation and composting, and 9.3.7 Rate changes in decay of biological material. Each one has a worked solution and a mark scheme showing where the marks go.