Sound wave
The region of spread out particles in a wave is called the trough. This is where the particles are at their lowest point of displacement from their equilibrium position.
Sound does not spread out in particles but in waves. Imagine dropping a pebble in a still lake...and that is how sound waves spread out. Sound waves can also reverberate through harder materials; however, soft materials absorb the vibrations.
When particles separate and spread evenly throughout a mixture, it is called diffusion.
Rarefaction is the part of a longitudinal wave where the particles are spread apart.
It is called diffusion when particles spread far apart and fill all the space available.
Those particles are called solutes. They are substances that are dissolved in a liquid, such as salt in water.
a suspension
it is called a liquid
if this is about the motion of the particles,it is brownian motion.the random motion of the particles.
wavelength
The spread out portion of a compression wave is called a rarefaction. In a compression wave, the particles are compressed together in the compression phase and spread out in the rarefaction phase.
You think probable to aerosols.