Brownian motion
What is Brownian motion?
It is the random motion of particles. Remark: The Brownian motion was named after Robert Brown, a British botanist. He observed through microscope that some very tiny particles of pollen in suspension of water move about continuously in a haphazard manner.
Explain why the smoke particles move in a haphazard way.
Air contains tiny particles, such as atoms and molecules, which are invisible under a tiny microscope. These tiny particles move randomly in all directions and collide the larger particles in the air, such as smoke particles. Due to uneven bombardment by these tiny particles, the smoke particles are seen to move in a haphazard way.
How do we demonstrate Brownian motion?
Brownian motion can be demonstrated by observing the smoke particles in air through a microscope. Remark: We cannot see the molecules or atoms of gases in air because they are very small. They are invisible under a laboratory microscope. They can only be seen by using a more powerful microscope, such as an electron microscope.
Describe Brownian motion under a microscope.
Some smoke particles are released into the glass container. The glass container is then covered up to keep the smoke and air inside the container. When observed under a microscope. the smoke particles can be seen near the glass container with the help of light. The smoke particles are observed to scatter or move in a haphazard way in the container.
