The model is intended for demonstration of Brownian motion of molecules at physics lessons at a secondary school.

The model is a transparent container with small balls and a washer inside.

The movement of the balls is accomplished by mechanical vibrations of the side walls of the device.

The device for demonstration of Brownian motion model allows to show by shadow projection on the screen an approximate picture (model) of molecular motion in gases.

Before the demonstration, the device should be explained to the students.

The balls are models of molecules, and the rubber stopper is a Brownian particle, invisible to the naked eye but clearly observable in a microscope.

Turning the percussion knob sets the balls in chaotic motion.

As a result of collisions with the balls, the rubber stopper is also in disorderly motion.

It moves due to the uneven bombardment of it by balls from different directions.

The movement of the rubber plug simulates the movement of a suspended particle observed in a microscope, i.e. Brownian motion.

The device is used in conjunction with a graph projector.