Animations and Videos: Changing Substances

These downloadable videos and animations are part of the multimedia package Stuff and Substance, and are intended to be used to establish the concept of a substance. The individual video and animation files are provided separately here to allow flexibility in their use. The Stuff and Substance multimedia package provides a series of interactive pages that can be used by teachers or students in the classroom, including supporting commentary and questions, animations, videos, images, and teachers’ notes.

Key steps in the development of understanding are:

• Defining a substance in terms of atoms and recognising two types of structures: molecular structures; and giant structures.
• Using ideas of atoms and substances to predict the possibility of substances changing into other substances i.e. chemical change.
• Some chemical reactions take place spontaneously on mixing at room temperature.
• Some chemical reactions only take place on heating to higher temperatures.
• Some chemical reactions take place between substances in solution.
• Decomposition is an example of a substance on its own undergoing chemical change.
• Some crystals incorporate water molecules within their structures.