Reason For Learning
The behaviour of gases is easy to predict because the particles of a gas are far apart and so don’t interact with each other very much. The study of gases is made easier by the fact that, in many ways, they all behave similarly. This enables us to draw convenient generalisations about their behaviour, including the ‘gas laws’. Gases have low densities, are compressible and mix easily. Hot air balloons use the properties of gases to achieve flight. A large fan is used to blow air into the balloon. Once in?ated, the air is heated using a propane burner. The molecules move more rapidly, hitting each other in a random chaotic motion. As they move further apart, the density of the air decreases. The balloon rises because the air inside is warmer, and therefore lighter, than the surrounding air.
In this learning bite you will examine:• properties that are common to all gases
• the kinetic molecular theory of gases to explain and predict their behaviour
• the units used for pressure, volume and temperature
Key Vocabulary Terms