Question

what is specific gravity?

Answer 1

Specific gravity is a dimensionless quantity; that is, it is not expressed in units.Specific gravity is the density of a substance relative to some reference substance.Specific gravity =density of substance
density of reference substance
example :-Water has a specific gravity equal to 1...

Answer 2

Specific gravity is the ratio of density of a substance to density of water. It is a number. It has no units.

For example:
density of mercury is 13600 kg/m³.
density of water is 1000 kg/m³.
Specific gravity of mercury = 13600/1000 = 13.6