What does reactivity describe in chemistry?

Reactivity in chemistry refers to how readily a substance interacts with other chemicals. This property is crucial in determining how substances will behave in reactions, including how they will combine with or influence other elements or compounds. A highly reactive substance will readily engage in chemical reactions, often under mild conditions, whereas a less reactive substance may require specific conditions, such as elevated temperatures or the presence of a catalyst, to react.

Understanding reactivity helps chemists predict the behavior of substances in various situations, including in laboratory experiments and industrial processes. For instance, metals like sodium react vigorously with water, while noble gases, like helium, are known for their low reactivity.