Le Chatelier's principle
It is used to show how the point of equilibrium of a system will move to oppose a change in the conditions of the system, following Newton's third law. This is most commonly seen in reversible reactions in chemistry, where a chemical reaction has reached a point where the formation of products happens at the same rate the products decay back into reactants. This principle can then be used to increase the amount of desired products made by moving equilibrium towards that side in chemical industries.