Properties of Matter

Pressure in gases

Teaching Guidance for 11-14 Supporting Physics Teaching

Pressure from particles

Wrong Track: How can there be pressure inside gases? They're too thin, they're not like water.

Right Lines: The air around us has a pressure just like water. This air pressure is due to the bombardment of air molecules. We don't notice air pressure until air is removed from one side of a surface (remove air from a Coke can and the air on the outside crushes the walls inwards).

Starting with liquids

Thinking about the learning

Pupils will readily accept the idea of pressure existing in liquids because it is a familiar phenomenon. However they may have problems in accepting that gases, such as the air around them, exert pressures.

Thinking about the teaching

Given that pupils are more familiar with pressure in liquids we recommend that you start with examples involving liquids and then move on to gases.

2023 IOP Awards

Teachers of Physics Awards

Recognising and celebrating outstanding contributions to the field of physics education.

Learn more