Explanation

The specific gravity of a solid is the ratio of its density to the density of a reference material, typically water. To find the specific gravity of a solid if its density is known, you can divide its density by the density of water.

The density of water at 4 degree Celsius is 1 g/cm^3, so to find the specific gravity of the solid with a density of 19.5 g/cm^3: 19.5 g/cm^3 (density of solid) / 1 g/cm^3 (density of water) = 19.5 (specific gravity)

Therefore, the specific gravity of the solid is 19.5.