Temperature is a quantitative measure of the degree to which an object is "cold" or "hot."


The Celsius (oC) and Fahrenheit (oF) scales measure relative temperatures. These scales compare the temperature being measured with arbitrary standards such as boiling water and an ice-water bath. The Kelvin scale measures absolute temperatures. On this scale, the temperature of an object is compared with the temperature at which the volume and pressure of an ideal gas extrapolate to zero.

Temperature is an intensive property, which does not depend on the size of the sample. When we mix two 50-mL samples of water at 20oC, for example, the mass doubles and the volume doubles, but the temperature remains the same.