Gas pressure arises from the constant, random bombardment of container walls by gas particles:
- Gas particles are in constant random motion
- They collide with container walls
- Each collision exerts a tiny force on the wall (Newton's 3rd law)
- Billions of collisions per second = measurable pressure
What happens when temperature increases:
- Particles gain kinetic energy (move faster)
- More frequent collisions (particles cover more distance per second)
- Harder collisions (more momentum transferred to walls)
- Result: Pressure increases
Quick Check: A gas is heated in a sealed, rigid container. Explain, using the particle model, why the pressure increases.
Heating the gas increases the kinetic energy of the particles, so they move faster. This causes more frequent collisions with the container walls, and each collision is harder (more force). The increased rate and force of collisions means greater pressure on the walls.
This deep dive covers The Particle Explanation of Gas Pressure within Gas Pressure & Temperature for GCSE Physics. Revise Gas Pressure & Temperature in Particle Model for GCSE Physics with 29 exam-style questions and 30 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 3 of 11 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Gas Pressure & Temperature
A sealed gas container is heated. What happens to the pressure of the gas inside?
A sealed gas cylinder is heated. Explain, using particle theory, why the pressure of the gas increases when the temperature increases.