What does a catalyst provide to a chemical reaction?

A catalyst plays a crucial role in chemical reactions by providing an alternative pathway with lower activation energy. Activation energy is the minimum energy required for reactants to undergo a chemical transformation. When a catalyst is present, it enables the reaction to proceed more easily, lowering the energy barrier that must be overcome for reactants to transform into products.

This means that reactions can occur at lower temperatures and often proceed faster than they would without the catalyst. Importantly, a catalyst itself is not consumed in the reaction and can be reused multiple times, which differentiates it from reactants and products.

The other options do not accurately describe the role of a catalyst. For example, while increasing temperature can indeed speed up a reaction, it's not a function of the catalyst itself. Similarly, a catalyst does not cause a permanent chemical change in itself, nor does it change the concentration of reactants directly; its function is solely to enhance the efficiency of the reaction path.