Entropy is a measure of the disorder present in a system. Entropy is disorder or randomness.

Entropy is a thermodynamic quantity, its value is equal to the amount of heat absorbed or emitted divided by the thermodynamic temperature (the absolute temperature, in Kelvin). The units of entropy are joules per Kelvin per mole. In chemical equations entropy is normally given the symbol S. The higher the entropy value the more disordered a system is, so for example of the three states of matter a gas, with the greatest degree of disorder, has the highest entropy value. Next are liquids and finally of the three states of matter the most ordered form are the solids and they have the lowest degree of entropy. Any change that increases entropy is a positive entropy change. Most spontaneous thermodynamic processes are accompanied by an increase in entropy.

Entropy is a measure of...