Experiment on Brownian motion

Apparatus: Microscope, Torchlight, Glass cell containing dust particles
Steps: 1) Set up a microscope
       2) Seal the glass cell containing some smoke particles and place them under the microscope
       3) Focus the microscope to see the smoke particles. the   smoke particles will appear as bright dots.
Observation: 1) Smoke particles move in random motion and         direction.
             2) The larger the particles, the slower the motion
Conclusion: Irregular motion of smoke is due to uneven           bombardment of air molecules of the smoke particles.