Question

Name two processes which provide the best evidence for the motion of particles in matter.

Answer 1

Two process which provides the best evidence for the motion of particles in matter are :

1. Brownian Motion
2. Diffusion.

Brownian Motion
$\to$ The best evidence for existence and movement of particles in liquids was given by Robert Brown.
$\to$ The zig zag movement of the small particles suspended in a liquid or gas.

Diffusion:
The spreading and mixing of a substance with another substances due to its motion of its particles is called Diffusion.

The existence of Brownian motion and diffusion gives us two conclusions about:
$\to$that matter is made up of tiny particles.
$\to$That the particles of matter are constantly moving.