Which of these scenarios involve a reaction that is at equilibrium?
a. the reaction is producing reactants and products at an equal rate.
b. the reaction is producing more reactants than products.
c. the reaction is only producing products
d. the reaction is producing more products than reactants.

a. the reaction is producing reactants and products at an equal rate. is the  correct answer.

Explanation:

If a reaction is at equilibrium then the reaction rates for both the reverse and forward directions are equal.

catalyst that increases the reaction rate of a  reaction, but it does not change the equilibrium state for that reaction.

Thus at the equilibrium stage, the concentration of the reactants and the product remain constant.

a plasma is a warm ionized gasoline consisting of approximately equal numbers of definitely charged ions and negatively charged electrons. the characteristics of plasmas are notably unique from the ones of ordinary neutral gases in order that plasmas are considered a awesome "fourth kingdom of remember."

d.) circle motion requires a force to give it a centripetal acceleration.