Number density
= Number density
{wiki=Number_density}
Number density is a physical quantity that describes the concentration of a number of particles, such as atoms, molecules, or other entities, in a given volume of space. It is typically represented by the symbol \\( n \\) and is measured in units of particles per unit volume, such as particles per cubic meter (m⁻³) or particles per cubic centimeter (cm⁻³).