Editing Chemistry (section)

====Compound====
[[File:Carbon dioxide structure.png|thumb|left|upright=0.6|[[Carbon dioxide]] (CO<sub>2</sub>), an example of a chemical compound]]
{{Main|Chemical compound}}

A ''compound'' is a pure chemical substance composed of more than one element. The properties of a compound bear little similarity to those of its elements.{{sfn|Burrows|Holman|Parsons|Pilling|2009|p=12}} The standard nomenclature of compounds is set by the [[International Union of Pure and Applied Chemistry]] (IUPAC). [[Organic compound]]s are named according to the [[organic nomenclature]] system.<ref>{{cite web |url=http://www.acdlabs.com/iupac/nomenclature/ |title=IUPAC Nomenclature of Organic Chemistry |publisher=Acdlabs.com |access-date=12 June 2011 |archive-date=8 June 2011 |archive-url=https://web.archive.org/web/20110608140820/http://www.acdlabs.com/iupac/nomenclature/ |url-status=live }}</ref> The names for [[inorganic compound]]s are created according to the [[inorganic nomenclature]] system. When a compound has more than one component, then they are divided into two classes, the electropositive and the electronegative components.<ref name="IUPAC">{{cite book |last1=Connelly |first1=Neil G. |last2=Damhus |first2=Ture |last3=Hartshom |first3=Richard M. |last4=Hutton |first4=Alan T. |title=Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005. |date=2005 |publisher=Royal Society of Chemistry Publishing / IUPAC |location=Cambridge |isbn=0854044388 |url=https://archive.org/details/nomenclatureinor2005conn |access-date=13 June 2022}}</ref> In addition the [[Chemical Abstracts Service|Chemical Abstracts Service (CAS)]] has devised a method to index chemical substances. In this scheme each chemical substance is identifiable by a number known as its [[CAS registry number]].