Absolute Zero
- The amount of pressure that a gas exerts on its container is dependent on the temperature of the gas
- This is because particles move with more energy as their temperature increases
- As the temperature of the gas decreases, the pressure on the container also decreases
- In 1848, Mathematician and Physicist, Lord Kelvin, recognised that there must be a temperature at which the particles in a gas exert no pressure
- At this temperature they must no longer be moving, and hence not colliding with their container
- This temperature is called absolute zero and is equal to -273 °C
At absolute zero, or -273 °C, particles will have no net movement. It is therefore not possible to have a lower temperature
- Absolute zero is defined as:
The temperature at which the molecules in a substance have zero kinetic energy
- This means for a system at absolute zero, it is not possible to remove any more energy from it
- Even in space, the temperature is roughly 2.7 °C above absolute zero