Sorting machines

During Key Stage 2, children will develop their understanding of the fact that materials can be divided into solids, liquids and gases. Through investigative work they should discover that some solids, such as salt, will dissolve in water to give solutions, while others, such as sand and chalk, will not. Children will also learn that some substances are insoluble and can be separated from liquids, and that the process of removing dissolved substances from a liquid is called evaporation: the liquid is heated until it evaporates, leaving behind the solid. Some children will go on to investigate the varying ways in which different solids dissolve in a given amount of water, and find that there is a limit to the mass of solid that can dissolve in a given amount of water. The activities on these pages specifically focus on the ways in which solids can be mixed and sometimes be separated; children also will learn that they often can ‘get back’ solids that have been mixed together.

Ages 7-9

Sieve sorters