In chemistry, Le Châtelier's principle, also called Chatelier's principle or "The Equilibrium Law", can be used to predict the effect of a change in conditions on a chemical equilibrium. The principle is named after Henry Louis Le Châtelier and sometimes Karl Ferdinand Braun who discovered it independently. It can be stated as:

When any system at equilibrium is subjected to change in concentration, temperature, volume, or pressure, then the system readjusts itself to (partially) counteract the effect of the applied change and a new equilibrium is established.

or whenever a system in equilibrium is disturbed the system will adjust itself in such a way that the effect of the change will be nullified. (in short)