Density Definition in Science

What Is Density Definition
Density is the amount of mass in a unit of volume. In a liquid, the portion with the highest density is at the bottom of the container.

By definition, density is mass per unit volume. In other words, it is the amount of matter packed into a space.

The symbol most commonly used for density is ρ (the lower case Greek letter rho). The capital letter D is also used. Density is an intensive property of matter, which means the size of a sample does not affect its value. It is a physical property of matter, meaning you measure density without requiring any chemical reaction. Density commonly is expressed in units of grams per milliliter and kilograms per liter.

Density Formula

The equation for density is:

density = mass / volume

ρ = m/V

The reciprocal of density (V/m) is its specific volume.

Density Examples

Density tends to be higher for solids than for liquids, which are in turn more dense than gases. For example, the density of iron is 7.87 g/ml. The density of pure water (a defined value) is 1 gram per milliliter. The density of air is only about 0.012 g/ml.

Common Misspellings

The two most common misspelling of density are dencity and densety.


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