What is true when a reaction has reached equilibrium

Answer : When a reaction has reached equilibrium then the rates of the forward and reverse reactions are equal.

Explanation :

Equilibrium reaction : It is a reaction which do not go on completion that means the reactant forms product and the products goes back to the reactants simultaneously.

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

Equilibrium state is the state when the reactants and products are present but the concentrations does not change with time that means there is no changes in the concentration the products and reactants.

Hence, when a reaction has reached equilibrium then the rates of the forward and reverse reactions are equal.

the answer is c.the valence of the atoms combine .