Particle Motion in Gases

• Particle model


  Helps explain how temperature, pressure, volume and energy in kinetic stores are related
• Average energy in kinetic stores

  Is related to temperature
• Increasing temperature of a gas

  Transfers energy into the kinetic energy stores of its particles
• Temperature of a gas

  Is related to the average energy in the kinetic energy stores of the particles in the gas
• Increasing temperature of a gas

  Increases the average speed of its particles
• Colliding gas particles


  Create pressure
• Gas particles colliding with something

  Exert a force (and so a pressure) on it
• Faster particles and more frequent collisions

  Lead to an increase in net force, and so gas pressure
• Increasing temperature of a gas

  Increases the speed of the particles, and so the pressure
• Increasing the volume of a gas

  Decreases the gas pressure
• Pressure and volume


  Are inversely proportional
• For a gas of fixed mass at a constant temperature, the relationship is: PV = constant