Which statement correctly describes a chemical equilibrium? it must take place in an open system the mass of the reactants and the mass of the products are no equal it is affected by the addition of a catalyst it does not involve a reversible reaction the concentrations of reactants and products are equal

Which activity describes an application of topographic maps? check all that apply. recreation, such as camping and hiking engineering, such as the construction of roads and buildings science, such as mapping stars in the sky business, such as analyzing population centers science, such as analyzing surface features