The specific gravity of mercury would remain the same on the moon, even though the gravitational force is weaker there.

Here's why:

* Specific gravity is the ratio of the density of a substance to the density of a reference substance, usually water.

* Density is a property of the material itself and is defined as mass per unit volume.

* Gravity affects the weight of an object, but not its mass or volume.

Since the mass and volume of a sample of mercury remain constant regardless of the gravitational field, its density and therefore its specific gravity would not change.

In essence, specific gravity is an intrinsic property of the substance and is independent of the gravitational field.