Which of the following best defines an extensive property?

An extensive property is defined as a physical property that depends on the amount of substance present. In this context, mass is a prime example of an extensive property because it directly correlates with how much of the substance you have; the greater the quantity of a substance, the greater its mass. When considering a sample of substance, if the amount increases, the mass will also increase proportionally.

In contrast, other properties such as density, color, and temperature do not change with the quantity of material. For instance, density is a ratio of mass to volume and remains constant regardless of the amount of substance provided that it is uniform; color is an inherent quality of the substance that does not vary with size; and temperature measures the average kinetic energy of the molecules in a sample, also independent of the total mass of the substance.