In chemistry, a chemical substance is state of matter characterized by the entities, i.e. atoms, molecules, chemical species, formula units, etc., that it is composed of; characterized by physical properties, such as refractive index, electric conductivity, melting point, etc. [1] A typical chemical substance, such as water, H20, is often defined as a material with a definite chemical composition. [2]
References
1. (a) Chemical substance – IUPAC Goldbook.
(b) Pure substance – DiracDelta Science & Engineering Encyclopedia.
2. Hill, J. W.; Petrucci, R. H.; McCreary, T. W.; Perry, S. S. (2005). General Chemistry, 4th ed., p5, Pearson Prentice Hall, Upper Saddle River, New Jersey.
Further reading
● Lewis, Gilbert N. and Randall, Merle. (1923). Thermodynamics and the Free Energy of Chemical Substances. McGraw-Hill.
