Number density

In physics, number density is the number of certain objects (particles, sound waves, galaxies, copies of Physics World, etc.) per volume:


 * $$n = \frac{N}{V} $$

where
 * n is the number density,
 * N is the total number of entities
 * V is the volume.

Conversely, the total number of entities can be written as


 * $$\iiint_V n\;dV = N $$

where
 * $$dV$$ is a volume element.

The number density of solutes in a solvent is called concentration.

Teilchendichte Densité de nombre 数密度 Koncentracja (fizyka) Концентрация частиц