Temperature, pressure and density are good examples. You also know that the density of the atmosphere is different from point to point, with air nearest the ground having the highest density and air far above the earth's surface having the lowest. On the other hand, it is silly to think of the volume of your swimming pool as being a property at a point. It is a characteristic of the entire swimming pool and that makes it extensive. A particularly important type of intensive property is the specific property , which is always given on a unit mass basis.
Specific properties are intensive because they exist at a point.
For instance, specific volume is simply the reciprocal of density. There is an important relationship between specific properties and extensive properties. Consider the case where the intensive properties of a system are uniform, meaning they are the same at each point within the system. This equation only works if the specific volume is constant throughout the system. Although this is not always true, it is often sufficiently accurate to assume so.