Question

Why do particles of matter move?

Answer 1

The states that all of the particles that make up matter are constantly in motion. As a result, all particles in matter have kinetic energy. ... The particles in a liquid, such as water in a pool, move much more freely than particles in a solid. They are constantly sliding around and tumbling over each other as they move.

Their power source is the rest of the universe. There is no such thing as an isolated particle, every particle exists in space and that space has structure. The interactions with other particles keep the particle moving. In terms of entropy, a pure motionless particle has 0 entropy, as it is in exactly one state. Any interaction with the universe tends to increase entropy by making the particle move.