At chemical equilibrium, the amount of (product and reactant is zero, product and reactant remains constant, product is zero) because (all molecules have the same activation energy, an equal number of molecules take part in the reaction, the rates of the forward and reverse reactions are equal)

At chemical equilibrium, the amount of product and reactant remains constant, because the rates of the forward and reverse reactions are equal.

Explanation:

At equilibrium, the forward and reverse rates become constant, so the concentrations of reactants and products also become constant.

product and reactant remains constant

the rates of the forward and reverse reactions are equal

Explanation:

The reactions which do not go on completion and in which the reactant forms product and the products goes back to the reactants simultaneously are known as equilibrium reactions.

Equilibrium state is the state when reactants and products are present but the concentrations does not change with time.

For a chemical equilibrium reaction, equilibrium state is achieved when the rate of forward reaction becomes equals to rate of the backward reaction.

Thus at chemical equilibrium, the amount of product and reactant remains constant because the rates of the forward and reverse reactions are equal.