Substance (chemistry)
In chemistry, substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combined without reacting, they may form a chemical mixture.
Extends: [General chemistry](https://wikipedia.org.ai/General chemistry), [Chemical substances](https://wikipedia.org.ai/Chemical substances), [Artificial materials](https://wikipedia.org.ai/Artificial materials)