According to the Bronsted-Lowry concept, what role does a chemical play when it accepts a proton?

In the Bronsted-Lowry theory of acids and bases, a fundamental concept is that an acid is defined as a substance that donates protons (H⁺ ions), while a base is a substance that accepts protons. Therefore, when a chemical accepts a proton, it is functioning as a base.

This distinction is crucial to understanding how various substances interact in acid-base reactions. For example, if ammonia (NH₃) accepts a proton, it becomes ammonium (NH₄⁺), clearly demonstrating its role as a base according to the Bronsted-Lowry framework.

In summary, when a chemical accepts a proton, it plays the role of a base, which aligns with the definition provided by the Bronsted-Lowry concept.