Solids, Liquids and Gases

This title supports the following learning objectives for Key Stage 2 science: Compare and group materials together, according to whether they are solids, liquids or gases; Observe that some materials change state when they are heated or cooled; Identify the part played by evaporation and condensation in the water cycle; Know that some materials dissolve in liquid to form a solution, and describe how to recover a substance from a solution; Use knowledge of solids, liquids and gases to decide how mixtures might be separated, including through filtering, sieving and evaporating; Demonstrate that dissolving, mixing and changes of state are reversible changes; Explain that some changes result in the formation of new materials, and that this is not usually reversible.