Substances can exist in three states of matter - solid, liquid and gas. Substances can change states. To change the state of a substance energy must be transferred to, or from, the substance.

Although the three states of matter are solid, liquid, and gas, not all substances seem to fit perfectly into one of these groups. Take a look at the substance below and see if you can decide whether ...

After viewing a model of salt, students help develop models for the processes of salt dissolving, water evaporating to form a gas, and salt re-forming as a crystal. The focus is that matter, whether ...

JOE:So how does it work? SEGE:'Well you see Joe, normally when substances heat up they transform from a solid and then a liquid before turning into a gas. 'Think about a regular ice cube melting.