Le Chatelier's Principle: This principle states that if a change (or 'stress') is applied to a system at equilibrium, the system will adjust itself to counteract this change.
Equilibrium Constant (K): A number that expresses the relationship between concentrations of reactants and products at equilibrium in terms of their stoichiometric coefficients.
Dynamic Equilibrium: This is when forward and reverse reactions occur at equal rates so there's no net change in concentrations of reactants and products even though reactions are still happening.