What is the type of motion witch is explained by particle theory?

Scientists have come up with a theory to explain why solids, liquids, and gases behave the way they do. The theory is called the Particle Theory.

The main ideas of the Particle Theory are:-

1 * all material is made up of tiny particles (known as "atoms")

2 * these particles are always moving

3 * the particles attract each other

These particles are too small to be seen. So how do scientists know that such small particles exist, and that they are moving? Why do scientists believe in this theory?

The best evidence or clue was first noticed by a scientist, Robert Brown in 1827. He saw pollen grains floating on water and noticed that they were moving around in a zigzag, haphazard way like a drunken man. He could see pollen grains through his microscope but not the tiny particles inside the water. These water particles were moving around and bumping into the pollen, making the grains jump around. Nowadays, this movement is called the Brownian Motion. Brownian motion is the scientists's best clue for the theory that all materials are made up of moving particles.

That time scientists could not figure out why it did like that. Now we know that it is because of the particles.

As the Brownian Motion could be explained by Particle Theory, it rightly verifies the existence of extremely small particles.

Brownian Motion is movement created where particles in both gases and liquids (known as fluids collectively) move randomly. The motion is caused by particles jostling other particles in the fluid. This motion is explained by the particle theory.

Particle theory or kinetic theory of matter theorizes that all matters (solid, liquid, gas) are formed by many particles which are constantly moving.