- Introduce the word 'pneumatics'; ask about experiences of gases under pressure,
eg bicycle tyre ('pneu' - French for tyre). Remind pupils of the nature of gases and liquids as described by the particle model of matter, and elicit their ideas about why gases - unlike liquids - are compressible. Offer pupils empty syringes to show this, if required. Spray aerosol air freshener and elicit pupils' ideas as to how the freshener gets out - gas under pressure acts as a propellant for the liquid. Establish why the pressurised container can explode when on the fire.
- The use of pressure to provide controlled movement could be demonstrated with a model steam engine, or pupils could find out about the work of,
eg Hero of Alexandria, Thomas Newcomen.
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- describe some effects and uses of gases under pressure,
eg car tyres, aerosols, pneumatic systems
- apply the model of the particle theory of matter to explain the behaviour of gases under pressure
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