Mass
mass
A [proper] fraction.
Yes.
It is a proper fraction.
You may be reaching for "fraction".
That is the specific gravity of the substance.
The number that compares an object's density to the density of water is called specific gravity. It is a unitless quantity representing the ratio of the density of a substance to the density of water.
A percent is a ratio, or rate, that compares a number to100
A ratio that compares the first number of two ratios Ex: 3/10 and 4/10 3/4 would be the part to part ratio
A balanced scale, which compares the mass of one object with that of a known quantity.
Specific gravity is a measurement that compares the density of an object to the density of water. It tells you how much heavier or lighter an object is compared to an equal volume of water.
A Part-to-part ratio