Define the term "reaction rate."

The term "reaction rate" refers to the speed at which reactants are transformed into products during a chemical reaction. It provides a measure of how quickly a reaction occurs, typically expressed in terms of the change in concentration of reactants or products over a specific period of time.

In this context, understanding the reaction rate is crucial because it allows chemists to predict how fast a reaction will proceed under various conditions, which can be influenced by factors such as temperature, concentration, and the presence of catalysts. The emphasis on the conversion of reactants to products highlights that reaction rates are not just about the formation of products but also reflect the dynamics of the reaction process itself.

Other options address different concepts. While temperature changes can indicate a reaction's progress, they do not define the reaction rate. Similarly, measuring the amount of product formed per minute touches on a specific way to express reaction rates but does not encompass the broader idea of reactant conversion speed. Lastly, discussing concentration changes of reactants is also related to the reaction rate, but it doesn't fully articulate the notion of speed or transformation central to the definition of a reaction rate.