Editing Chemical formula (section)

=== Chemical names in answer to limitations of chemical formulae ===<!-- what why here??? -->
{{main|Chemical nomenclature}}
The alkene called [[but-2-ene]] has two isomers, which the chemical formula {{chem2|CH3CH\dCHCH3}} does not identify. The relative position of the two methyl groups must be indicated by additional notation denoting whether the methyl groups are on the same side of the double bond (''cis'' or ''Z'') or on the opposite sides from each other (''trans'' or ''E'').<ref>{{Cite book|last=Burrows, Andrew.|title=Chemistry³ : introducing inorganic, organic and physical chemistry|isbn=978-0-19-969185-2|edition=Second|location=Oxford|oclc=818450212|date=2013-03-21 |publisher=Oxford University Press}}</ref>

As noted above, in order to represent the full structural formulae of many complex organic and inorganic compounds, [[chemical nomenclature]] may be needed which goes well beyond the available resources used above in simple condensed formulae. See [[IUPAC nomenclature of organic chemistry]] and [[IUPAC nomenclature of inorganic chemistry|IUPAC nomenclature of inorganic chemistry 2005]] for examples. In addition, linear naming systems such as [[International Chemical Identifier]] (InChI) allow a computer to construct a structural formula, and [[simplified molecular-input line-entry system]] (SMILES) allows a more human-readable ASCII input. However, all these nomenclature systems go beyond the standards of chemical formulae, and technically are chemical naming systems, not formula systems.<ref>{{Cite web |last=Miles |first=Linda |title=LibGuides: CHE 120 - Introduction to Organic Chemistry - Textbook: Chapter 1 - Organic Chemistry Review / Hydrocarbons |url=https://guides.hostos.cuny.edu/che120/chapter1 |access-date=2024-07-13 |website=guides.hostos.cuny.edu |language=en}}</ref>