What is a catalyst in a chemical reaction?

A catalyst is defined as a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change. This means that it can help reactants convert into products more quickly, facilitating the reaction process by providing an alternative pathway with a lower activation energy. This unique property of catalysts is crucial in many chemical processes, allowing reactions to occur faster and often at lower temperatures.

While other options mention slowing down reactions or reducing energy usage, these do not accurately describe the function of a catalyst. By definition, a catalyst enhances the reaction rate and is not a byproduct, as it remains unchanged after the reaction. Understanding the role of a catalyst is essential in fields such as chemistry and cosmetology, particularly when working with products that utilize chemical reactions for curing or setting processes.