Final answer:
Specific gravity is a ratio comparing the density of a substance to that of water. A specific gravity above one indicates that the substance is denser than water and will typically sink when placed in water.
Step-by-step explanation:
When we discuss specific gravity, we refer to the ratio of the density of a substance compared to the density of water. Specifically, specific gravity is a dimensionless value as it does not depend on the units of density used for the calculation. A specific gravity above one indicates that the substance in question is denser than water.
This typically means that, if placed in water, the substance will sink. To illustrate, battery acid and radiator fluid have specific gravities that can be measured to assess their condition. Conversely, a specific gravity less than one would imply a substance is less dense than water, and it would float.