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    IsotopeAtomic mass (Da)Isotopic abundance (amount fraction)
    23Na22.989 769 28(2)1

    Sodium is a monoisotopic element and its atomic weight is determined solely by its isotope 23Na. The Commission last revised the standard atomic weight of sodium in 2005 based on the latest Atomic Mass Evaluation by IUPAP.

    SOURCE  Atomic weights of the elements: Review 2000 by John R de Laeter et al. Pure Appl. Chem. 2003 (75) 683-800
    © IUPAC 2003


    Ar(Na) = 22.989 769 28(2) since 2005

    The name derives from the English soda and Latin sodanum for "headache remedy". The symbol Na derives from the Latin natrium for "natron" (soda in English). Sodium was discovered in 1807 by the English chemist Humphry Davy from electrolysis of caustic soda (NaOH).