| − | Closely related to density, ''specific gravity'' is a dimensionless ratio of the density of the substance to the density of a standard--typically another substance, usually a liquid, in which the substance in question is suspended. The usual standard of specific gravity is water, in which case the specific gravity is numerically equivalent to the density. But one can also define the specific gravity of a substance in, for example, an organic liquid, such as benzene. | + | Closely related to density, ''[[specific gravity]]'' is a [[dimensionless]] ratio of the density of the substance to the density of a standard--typically another substance, usually a liquid, in which the substance in question is suspended. The usual standard of specific gravity is water, in which case the specific gravity is numerically equivalent to the density. But one can also define the specific gravity of a substance in, for example, an organic liquid, such as benzene. |