Density is a physical property because its measurement or observation does not alter the chemical composition of a substance. Other physical properties include color, texture, melting point and volume. When a chemical property, such as flammability or oxidation, is observed, one substance changes into another.
Density describes the mass per unit volume of a substance. It is an intensive property of a substance, which means density is the same no matter the shape or amount of the substance. To determine the density of something, its mass, typically measured in grams, is divided by its volume, usually measured in milliliters or liters. For example, the density of water is 1 g/ml, while the density of ice, which floats in water, is slightly less at 0.917 g/ml. Gold's density is significantly greater at 19.31 g/ml.