20 Which term is defined as a measure of the disorder of a system?

(1) heat (3) kinetic energy

(2) entropy (4) activation energy

Entropy is the term defined as a measure of the disorder of a system. This occurs mainly when the thermal energy is not available for the mechanical things.

Heat is a measure of energy in a medium

Kinetic energy is a measure of energy in an object that's resulting in movement

Activation energy is the amount of energy required to start a chemical reaction

Entropy is a measure of disorder in a system

The answer is Entropy