In [[chemistry]] and [[physics]], an '''atom''' ([[Greek language|Greek]] ''ἄτομος'' or ''átomos'' meaning "indivisible") is the smallest particle still characterizing a [[chemical element]]."Atom" in IUPAC Compendium of Chemical Terminology, Electronic version, [http://goldbook.iupac.org/A00493.html]. Accessed March 2007. | In [[chemistry]] and [[physics]], an '''atom''' ([[Greek language|Greek]] ''ἄτομος'' or ''átomos'' meaning "indivisible") is the smallest particle still characterizing a [[chemical element]]."Atom" in IUPAC Compendium of Chemical Terminology, Electronic version, [http://goldbook.iupac.org/A00493.html]. Accessed March 2007. |