# Density Definition in Science

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.

### References

• Serway, Raymond; Jewett, John (2005). Principles of Physics: A Calculus-Based Text. Cengage Learning. ISBN 0-534-49143-X.
• Sharma, P. V. (1997). Environmental and Engineering Geophysics. Cambridge University Press. ISBN 9781139171168 doi:10.1017/CBO9781139171168
• Young, Hugh D.; Freedman, Roger A. (2012). University Physics with Modern Physics. ISBN 978-0-321-69686-1.