Final answer:
When a chemical system at equilibrium is disturbed, it counteracts the disturbance by shifting towards the products or reactants to re-establish equilibrium.
Step-by-step explanation:
When a chemical system at equilibrium is disturbed, it returns to equilibrium by counteracting the disturbance. The system will either shift towards the products or the reactants to re-establish equilibrium, depending on the change made. For example, if a reactant is added to the mixture, the equilibrium will shift towards the products to remove the added reactant and relieve the stress. This process is described by Le Chatelier's principle.