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    Yttrium

    IsotopeAtomic mass (Da)Isotopic abundance (amount fraction)
    89Y88.905 838(2)1

    Yttrium is a monoisotopic element and its atomic weight is determined solely by its isotope 89Y. The Commission last revised the standard atomic weight of yttrium in 2021 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

    CIAAW

    Yttrium
    Ar(Y) = 88.905 838(2) since 2021

    The name derives from the Swedish village of Ytterby where the mineral gadolinite was found. In 1794, the Finnish chemist Johan Gadolin discovered yttrium in the mineral ytterbite, which was later renamed gadolinite for Gadolin. Gadolin originally called the element ytterbium after ytterbite. The name was subsequently shortened to yttrium, and later another element was given the name ytterbium.