A substance that can act as both an acid and a base is referred to as?

A substance that can act as both an acid and a base is referred to as amphoteric. This term describes compounds that can donate protons (acting as acids) or accept protons (acting as bases) depending on the circumstances or the substances they are interacting with in a chemical reaction. The ability to operate in both roles makes amphoteric substances unique and versatile in various chemical environments.

For example, water is a common amphoteric substance; it can donate a hydrogen ion (acting as an acid) when reacting with a stronger base, or it can accept a hydrogen ion (acting as a base) when reacting with a stronger acid. This dual functionality is an important concept in acid-base chemistry and is foundational for understanding various reactions in biochemistry and environmental chemistry.