What is a solid?

This lesson introduces Year 4 pupils to the properties of solids, helping them understand that solids keep their shape because their particles are packed closely together. To explore this idea in a practical way, the class carries out a simple experiment in which they shake a jar of cream until it turns into butter. During the activity, pupils observe how the liquid cream gradually thickens and eventually becomes a solid that holds its shape. This hands-on investigation helps them see how a material can change state and reinforces their understanding of what makes a solid different from a liquid.