According to Bronsted-Lowry, what role does a base play in a reaction?

In the context of the Bronsted-Lowry theory, a base is defined as a substance that accepts protons (H⁺ ions) during a chemical reaction. This definition establishes the role of bases in facilitating the transfer of protons between reactants. When a base encounters a proton donor (an acid), it can effectively bind to that proton, increasing the concentration of the base's conjugate acid in the solution.

Understanding this concept is crucial because it emphasizes the interaction between acids and bases as vital in various chemical processes, including neutralizations, buffer solutions, and in metabolic pathways in biology. This proton acceptance leads to the formation of new chemical species and is foundational for predicting the outcomes of many chemical reactions.

In contrast, the other options relate to different concepts in chemistry, such as electron pair interactions and roles in other theories of acid-base chemistry. The distinction that a Bronsted-Lowry base is specifically a proton acceptor is central to understanding its behavior in reactions.