Plastics are made from natural materials such as wood, coal and oil. They can also be changed into synthetic materials with different properties. Plastic can be thin and transparent or thick and opaque. We see lots of examples of different types of plastic.
Students could be presented with objects made from a range of different materials including different kinds of plastic (polythene, polystyrene), wood, metal or stone. They could then be asked to develop their own criteria for sorting these objects, and in doing so discuss the properties of each material. The plastic objects could then be presented to students in isolation and their properties considered in more depth. Students could create a list of things they can find in the classroom that are made of plastic and consider why this material was chosen. Challenge students to design an experiment to test a particular property such as flexibility, strength or transparency.
Students could also recap what plastics are made of, as presented in this clip. They could discuss the ways in which its properties have changed from its original source.