What is substance in chemistry

A chemical substance is matter of regular nature, which is defined by the elementary units of which it is composed. These elementary units can be atoms, molecules or formula units (for example in the case of salts). Chemical substances are characterized by their physical properties, such as density, melting point, electrical conductivity, etc.[1]

Every substance has a mass, has a volume (space requirement) and has internal energy (thermal energy). Chemical substances are also used colloquially with the word substance referred to, which in the language of chemistry is restricted to substances in solid form.

A distinction is made between pure substances (elements or compounds) and mixtures.

A reaction scheme can be specified for the conversion of a substance into one or more other substances (a chemical reaction). The existence of substances is proven in chemistry by means of detection reactions. Here, specific, qualitative detection reactions - in particular from qualitative inorganic chemistry, i.e. for anions and cations - are clearly and methodically described. The quantitative (often highly precise) determination is carried out with the help of modern, instrumental analysis methods (instrumental analysis).


  1. Translated to: IUPAC Compendium of Chemical Terminology, Electronic version: http://goldbook.iupac.org/C01039.html, accessed on Aug. 18, 2007.

See also

Category: Chemistry