Final answer:
Equilibrium is the state in a chemical reaction where the forward and reverse reactions occur at an equal rate, resulting in no net change in reactant and product concentrations, referred to as a dynamic equilibrium.
Step-by-step explanation:
The situation where two opposite processes are occurring at equal rates, and no net change is taking place, is called equilibrium. In the context of a chemical reaction, equilibrium is achieved when the forward reaction and the reverse reaction proceed at the same rate. This does not mean that the concentrations of reactants and products are equal, but rather that their concentrations cease to change over time. This concept is often represented with a double arrow in chemical equations to indicate a dynamic equilibrium, signifying ongoing, reciprocal processes even though the macroscopic properties remain constant.