GCSE Physics revision

Particle motion in gases+Z6:AB6

Particle model and pressure

AQA 4.3.3.1

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AQA student objectives

Learning pathway

ALL 🎯

Explain how gas-particle motion relates to temperature and pressure, including how temperature affects pressure at constant volume.

MOST 🎯🎯

Apply the scientific explanation of particle motion in gases+z6:ab6 to a relevant example.

SOME 🎯🎯🎯

Analyse a new situation involving particle motion in gases+z6:ab6 and explain the scientific reasoning.

Revision summary

Read on screen, then print for Cornell-style active revision.

Gas molecules inside a closed container move constantly and randomly, meaning they travel at different speeds and in different directions.
There are millions of gas molecules in any container, and they continuously collide with each other and with the walls of the container.

Temperature is a measure of the average kinetic energy of the molecules in a substance.
Individual molecules have slightly different kinetic energies, and the average of all these values gives the temperature of the gas.
A higher temperature means the molecules have greater kinetic energy and therefore move more rapidly.

2. Temperature and Kinetic EnergyAQA

Temperature is a measure of the average kinetic energy of the molecules in a substance.
Individual molecules have slightly different kinetic energies, and the average of all these values gives the temperature of the gas.
A higher temperature means the molecules have greater kinetic energy and therefore move more rapidly.

Gas pressure is caused by the molecules colliding with the walls of the container.
The more frequently the molecules collide with the walls, the greater the pressure exerted on the container.

When the temperature of a gas increases, the molecules gain kinetic energy and move more rapidly.
Faster-moving molecules collide with the walls more frequently and with greater force, increasing the pressure.
This relationship between temperature and pressure only holds true when the volume of the container is kept constant.

4. Effect of Increasing Temperature on PressureAQA

When the temperature of a gas increases, the molecules gain kinetic energy and move more rapidly.
Faster-moving molecules collide with the walls more frequently and with greater force, increasing the pressure.
This relationship between temperature and pressure only holds true when the volume of the container is kept constant.

When the volume of a container is decreased, the gas molecules are confined to a smaller space.
In a smaller volume, molecules collide with the walls more frequently, which increases the pressure.
Molecules also collide with each other more often when the volume is reduced.

When the volume of a container is increased, the molecules have more space to move around in.
With more space, collisions with the walls become less frequent, resulting in a lower pressure.

Higher temperature leads to higher pressure when volume is kept constant, because molecules collide with the walls more often.
Higher pressure means more frequent collisions with the walls and between molecules themselves.
To observe the direct relationship between temperature and pressure, the volume must remain constant.

7. Linking Temperature, Pressure, and VolumeAQA

Higher temperature leads to higher pressure when volume is kept constant, because molecules collide with the walls more often.
Higher pressure means more frequent collisions with the walls and between molecules themselves.
To observe the direct relationship between temperature and pressure, the volume must remain constant.

Lower temperature less kinetic energy slower particle movement fewer wall collisions lower pressure.
Higher temperature more kinetic energy faster particle movement more wall collisions higher pressure.
Smaller volume more frequent wall collisions higher pressure, even if temperature stays the same.