DENSITY is a physical property of matter, as each element and compound has a unique density associated with it. Density defined in a qualitative manner as the measure of the relative "heaviness" of objects with a constant volume.Density may also refer to how closely "packed" or "crowded" the material appears to be.
To calculate:
| Density = | | g/mL |
| |
The units of density are typically g/cm3, but they can also have other designations that may be more convenient. The densities of various materials range from large values for heavy metals to very small values for gases.
In most cases, the density of an object can be used to predict whether it is a solid, liquid or a gas.
- Solids generally have a density greater than water (1 g/cm3). For example, aluminum has a density of 2.7 g/cm3. Yet, oak (0.75 g/cm3) is a solid and floats in water. Some exceptions are most varieties of wood, many plastics, and pumice.
- Liquids generally have a density near 1 g/cm3, with some being slightly above and some being slightly below. An exception is mercury (Hg), or quicksilver, which has a density of 13.6 g/cm3.
Matter with smaller density will float on top of the matter with bigger density.
The densities for some common substances are:
| Substance | Density (gm/cu.cm) |
| Air | 0.0013 |
| Wood (oak) | 0.85 |
| Water | 1.00 |
| Ice | 0.93 |
| Aluminum | 2.7 |
| Lead | 11.3 |
| Gold | 19.3 |
| Ethanol | 0.94 |
| Methanol | 0.79 |
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