What is the difference between an acid and a base in chemistry?

In chemistry, the distinction between acids and bases can be best understood through the Brønsted-Lowry definition, which describes acids as substances that donate protons (H⁺ ions) and bases as substances that accept protons. This is foundational in understanding how these two types of substances interact in chemical reactions.

When an acid donates a proton, it becomes a conjugate base, while a base that accepts a proton becomes a conjugate acid. This interaction is central to many biochemical processes and is crucial for understanding reaction mechanisms, acid-base equilibrium, and the behavior of substances in solution.

While other choices may contain elements of truth regarding the behavior and characteristics of acids and bases, the correct definition explicitly identifies the roles they play in proton transfer, which is the most fundamental aspect of their behavior in chemistry. This understanding is vital not only in theoretical contexts but also in practical applications, such as titrations, buffer solutions, and various chemical syntheses.