Which of the following describes a dynamic equilibrium?

A dynamic equilibrium occurs in a closed system where the forward and reverse reactions occur at the same rate, leading to constant concentrations of reactants and products over time. In this state, while individual molecules are continuously reacting, the overall concentration of substances remains stable. This is accurately described by the option stating that the system does not change; both reactions are occurring at equal rates.

In contrast, the first option indicates that the concentrations of reactants and products change continuously, which contradicts the concept of dynamic equilibrium where concentrations remain constant. The third option suggests that the reaction occurs only in one direction, which is not representative of dynamic equilibrium as it involves ongoing processes in both directions. Lastly, the fourth option, which mentions that products are always favored over reactants, can lead to misconceptions about the nature of equilibrium; while one side may be more favored, dynamic equilibrium refers to the balance achieved between the reactants and products, regardless of which side has higher concentrations.