Brownian motion. This is random motion of micro particles resultimg from collisions between the particle in question and other particles in the surrounding medium.
There are many kinds of particles and many kinds of motion, so there is more than one answer to that question. In many cases, particle motion is explained by Newtonian mechanics. In other cases, you would need quantum mechanics or Einstein's theory of relativity, or the Maxwell equations if the particles are photons.
The particles are tightly packed so they vibrate.
Brownian motion
The motion of particles is accelerated.
Brownian motion is the random moving and mixing of particles.
Brownian motion is the random moving and mixing of particles.
Quantum mechanics explains the unpredictable nature of the electron (and of subatomic particles in general).
Particles within are limited to vibrational motion, unlike the particles which make up liquids which can have vibrational & translational motion, and gaseous particles which have vibrational, translational and rotational motion.
Unless the particles collide
motion
if this is about the motion of the particles,it is brownian motion.the random motion of the particles.
Robert Brown discovered zigzag motion of particles. The behavior is called the Brownian motion or pedesis.