# density

## Definitions

### General Science

• noun the quantity of mass per unit of volume
• noun the amount of data that can be packed into a space on a disk or tape
• noun the number of individuals in a specific area

### Astronomy

• The amount of matter in a unit volume of material. Density is usually measured in grams per millilitre (or cubic centimetre, almost the same thing), a scale on which water has a density of one. On this scale the Earthâ€™s average density is 5.52gm/cc and that of the Moon 3.34, while the Sun is at 1.41 and a white dwarf in the region of 100 000 gm/cc.

### Construction

• In urban planning, the number of people living within an acre (or sometimes a square mile) of land.
• The ratio of the mass of a specimen of a substance to the volume of the specimen; the mass per unit volume of a substance.
• The closeness of pile yarn; the amount of pile packed into a given area of carpet, usually measured in ounces per square yard.
• The number of lots or building units per acre of land as determined by the zoning bylaw having jurisdiction.

### Electronics

• The mass of a given substance or body per unit volume.
• The concentration of a given entity per unit of a given totality, such as volume. For example, the logarithm of the ratio of incident light to transmitted light, the number of bits per unit area, the number of charge carriers in a semiconductor material per unit volume, or the number of logic gates per unit area of the surface of an IC.

### Food

• Mass or weight per unit volume. e.g. water has a density of 1 kg per litre, saturated brine about 1.22 kg per litre and vegetable oil about 0.8 kg per litre.
• The quality of hardness, thickness, opacity, etc. of something.

### Information & Library Science

• noun the level of darkness of an image

### Travel

• noun the number of people per unit of area
http://www.dictionarycentral.com/definition/density.html