When is equilibrium reached in a reversible reaction?

Equilibrium in a reversible reaction is reached when the rates of the forward and reverse reactions are equal. At this point, the concentrations of reactants and products remain constant over time, even though both reactions are still occurring. This means that the system has reached a dynamic balance where the production of products from reactants happens at the same rate as the conversion of products back into reactants.

Other options do not accurately define equilibrium: the concentration of reactants being higher does not indicate a balanced reaction; while temperature can play a role in the position of equilibrium, it is not a defining factor for when equilibrium is achieved; and the maximum concentration of products does not necessarily mean equilibrium is reached, as concentrations could stabilize at different levels without achieving balance.