The place in a wave where particles are far apart is called a rarefaction.

Here's a breakdown:

* Waves: Waves are disturbances that travel through a medium (like air, water, or a string) by transferring energy without transferring matter.

* Compression: In a wave, a compression is a region where the particles of the medium are close together.

* Rarefaction: In a wave, a rarefaction is a region where the particles of the medium are spread out, or far apart.

So, in a sound wave (which is a longitudinal wave), the compressions are areas of high pressure, and the rarefactions are areas of low pressure.