1. Introduce the idea of building a model of the water cycle. Remind students that they have seen and used drawings and animations as models of a solid, liquid, and gas. Tell students that they will ...

Most substances can exist as a solid, liquid or gas. They can change state, usually when they are heated or cooled. For example, liquid water turns into water vapour when it is heated enough ...

Substances can exist in three states of matter - solid, liquid and gas. All substances are made ... In a liquid like water, the particles are randomly arranged. They move freely over each other ...