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Standard and conventional atomic weights 2016 abridged to four significant digits


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Coplen, T.B., Meyers, F., and Holden, N.E., 2016, Standard and conventional atomic weights 2016 abridged to four significant digits: U.S. Geological Survey data release,


2016 four-figure standard and conventional atomic weights of the chemical elements


Point of Contact :
Tyler B Coplen
Originator :
Tyler B Coplen, Fabienne Meyers, Norman E Holden
Metadata Contact :
Tyler B Coplen
Publisher :
U.S. Geological Survey
Distributor :
U.S. Geological Survey - ScienceBase
USGS Mission Area :
Water Resources
SDC Data Owner :
National Research Program

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Standard_and_conventional_atomic_weights_2016_abridged_to_four_digits.pdf 228.18 KB application/pdf
Standard_and_conventional_atomic_weights_2016_abridged_to_four_digits.xlsx 58.87 KB application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Standard_and_conventional_atomic_weights_2016_abridged_to_four_digits.docx 63.2 KB application/vnd.openxmlformats-officedocument.wordprocessingml.document


To indicate that atomic weights of many elements are not constants of nature, in 2009 and 2011 the Commission on Isotopic Abundances and Atomic Weights (CIAAW) of the International Union of Pure and Applied Chemistry (IUPAC) replaced single-value standard atomic weight values with atomic weight intervals for 12 elements (hydrogen, lithium, boron, carbon, nitrogen, oxygen, magnesium, silicon, sulfur, chlorine, bromine, and thallium). CIAAW recognized that some users of atomic weight data only need representative values for these 12 elements, such as for trade and commerce. For this purpose, CIAAW provides conventional atomic weight values, and these values can serve in education when a single representative value is needed, such as for molecular weight calculations. Because values abridged to four figures are preferred by many educational users of atomic weights, conventional atomic weight values abridged to four figures for all 12 elements (except for lithium, which is three figures) have been determined and are presented in a table “Standard and conventional atomic weights 2016 abridged to four significant digits”.



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DOI doi:10.5066/F79Z9315

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