5.9 understand the significance of Brownian motion, as supporting evidence for particle theory

5.9 understand the significance of Brownian motion, as supporting evidence for particle theory

One piece of evidence for the continual motion of particles in a liquid or a gas is called Brownian motion. Particles of a liquid or gas are moving around continually and bump into each other and into tiny particles such as pollen grains. Sometimes there will be more collisions on one side of a pollen grain than on another, and this will make the pollen grain change its direction or speed of movement.