Combustion of gasoline in automobiles produces poisonous gases. Catalytic converters that contain solid platinum, palladium, and rhodium change these poisonous gases into harmless gases. Which statement describes the catalyst?

A catalyst speeds up a reaction by providing an alternative pathway with a lower activation energy. The platinum, palladium, and rhodium help convert poisonous gases into harmless ones without being consumed in the reaction. They do not increase the energy needed, and because they are solids reacting with gases, they are heterogeneous catalysts—not homogeneous ones.

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