Number density

Encyclopedia : N : NU : NUM : Number density

Number density in physics is a subtle generalization of the concept of density and refers to the number of objects (particles, sound waves, galaxies, etc.) per volume.

Number density can be written as

[n = \frac ]

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

Conversely, the total number of entities can be written as

[\int_V n\;d\tau = N ]

where [d\tau] is a volume element.

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

From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.