Brownian motion is the random movement of particles. It is possible to observe this movement under the microscope.
Materials: milk, water, slide, cover slip
- Dilute one drop of milk in about 5ml of water.
- Place one drop of the dilute milk on the microscope slide and place a cover slip on top of it.
- Observe under the microscope in bright field and in dark field. The microscopic fat droplets of the milk can be seen moving randomly. This is Brownian motion.
- Change the temperature by placing the slide into the refrigerator or by warming it up. Observe again. The Brownian motion is temperature dependent.