An extensive property is a physical quantity whose value is proportional to the size of the system it describes or to the quantity of matter in the system/02%3A_Matter_and_Change/2.04%3A_Extensive_and_Intensive_Properties). In other words, the magnitude of an extensive property changes as the size or amount of matter in the system changes. Examples of extensive properties include mass, volume, and entropy/02%3A_Matter_and_Change/2.04%3A_Extensive_and_Intensive_Properties). Extensive properties are additive for subsystems, meaning that the total value of an extensive property for a system is equal to the sum of the values of that property for its subsystems.

Dividing one extensive property by another extensive property generally gives an intensive value. An intensive property is a physical quantity that does not depend on the size of the system or the quantity of matter in the system. Examples of intensive properties include temperature, density, and color. The ratio of two extensive properties of the same object or system is an intensive property. For example, the ratio of an objects mass and volume, which are two extensive properties, is density, which is an intensive property.

In summary, an extensive property is a physical quantity that changes as the size or amount of matter in the system changes, while an intensive property is a physical quantity that does not depend on the size or amount of matter in the system.