New Atomic weight for Ytterbium

Atomic Weight of Ytterbium revised at BOKU.

The IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW) and its Subcommittee on Isotopic Abundance Measurements (SIAM) held its biennial meeting at BOKU from July, 31 to August 4.

Formally established in 1899, the Commission on Isotopic Abundances and Atomic Weights remains one of the oldest continuously serving scientific bodies. It was created in order to introduce uniformity in the atomic-weight values used worldwide. The Commission periodically and critically evaluates the published scientific literature and produces the Table of Standard Atomic Weights. These tables serve as primary source for atomic weight values worldwide for science, trade and also educational purposes. Thus, the values are also published in any periodic table of the elements printed in educational literature.

Today, the Commission consists of a group of approximately 20 experts in isotope mass spectrometry and measurement scientists as well as statisticians who are concerned with topics such as the measurement of isotopic abundances and variations of those abundances in natural materials, standard reference materials and uncertainty considerations linked to these topics. This year, the Commission was hosted by Thomas Prohaska (CIAAW Secretary) und Johanna Irrgeher (SIAM Chair).

Amongst other businesses, the Standard Atomic Weight of the element Ytterbium (Yb) was re-evaluated and changed.