Materials and their properties - what pupils should be taught

  Separating mixtures of materials

  • How to separate solid particles of different sizes by sieving, e.g. those in soil
  • That some solids, e.g. salt, sugar, dissolve in water to give solutions but some, e.g. sand, chalk, do not
  • How to separate insoluble solids from liquids by filtering
  • How to recover dissolved solids by evaporating the liquid from the solution
  • To use knowledge of solids, liquids and gases to decide how mixtures might be separated