An explanation of compounds is given, using plastic as an example. Mixtures are then described, using air as an example. The components of air are listed. These are then divided into atoms and molecules and an explanation of the difference given. These are then divided into elements and compounds and an explanation of the difference given.
Use this clip to explain the different ways in which atoms and molecules can be classified as elements and compounds. Students could then participate in 'chemical symbol' card games, working together to decide which substances are made up of single atoms or molecules, and whether they are elements or compounds.