Tyler B. Coplen Fabienne Meyers Norman E. Holden 2016 Table Reston, VA U.S. Geological Survey http://dx.doi.org/10.5066/F79Z9315 Tyler B. Coplen Fabienne Meyers Norman E. Holden 2016 Reston, Virginia U.S. Geological Survey 2016 four-figure standard and conventional atomic weights of the chemical elements 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”. The atomic weights of many elements are not invariant, but depend on the origin and treatment of the material. The standard atomic weights apply to elements of natural terrestrial origin. Although the atomic weights of some elements in some naturally occurring materials may differ from given values because of a variation in the mole fractions of an element’s stable isotopes, the last significant figure of each tabulated value is considered reliable to ±1 except for zinc, which is ±2. For twelve of these elements, both a conventional atomic weight and an atomic weight interval is given with the symbol [a, b] to denote the set of atomic weight values in normal materials; thus, a is less than or equal to the atomic weight and the atomic weight is less than or equal to b. For lithium, the conventional atomic weight is only three digits because of the large variation found in lithium-bearing reagents. 20161107 publication date Complete Not planned -180.0 180.0 90.0 -90.0 None atomic weights atomic weight standard atomic weights conventional atomic weight atomic weight interval USGS Metadata Identifier USGS:580a6a3ce4b0f497e7906b9c Not Applicable NA none none Tyler B. Coplen U.S. Geological Survey mailing and physical

Mail Stop 431, 12201 Sunrise Valley Drive

Reston Virginia 20192 USA 703-648-5862 tbcoplen@usgs.gov Environment as of Metadata Creation: Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.4.1 (Build 5686) Service Pack N/A (Build N/A) Authors and reviewers reviewed the data to ensure that it agreed with the manuscript text. Authors and reviewers reviewed the data to ensure that it agreed with the manuscript text. Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. No formal positional accuracy tests were conducted No formal positional accuracy tests were conducted Wieser, M. E., Holden, N., Coplen, T. B., Böhlke, J. K., Berglund, M., Brand, W. A., De Bièvre, P., Gröning, M., Loss, R. D., Meija, J., Hirata, T., Prohaska, T., Schoenberg, R., O’Connor, G., Walczyk, T., Yoneda, S., and Zhu, X.-K. 2013 Table Pure and Applied Chemistry, v. 85, p. 1047–1078 International Union of Pure and Applied Chemistry: www.iupac.org http://dx.doi.org/10.1351/PAC-REP-13-03-02 Atomic weight data 20100101 20111231 NA 2011 atomic weights To determine findings Coplen, T. B., Meyers, F., and Holden, N. E. 20161107 Table Reston, VA U.S. Geological Survey https://www.sciencebase.gov/catalog/item/5807af39e4b0841e59e3a43e Atomic weight data 19600101 20161107 NA 2016 Four-place table To determine findings International Union of Pure and Applied Chemistry: www.iupac.org 20160608 press release website International Union of Pure and Applied Chemistry: www.iupac.org https://iupac.org/iupac-is-naming-the-four-new-elements-nihonium-moscovium-tennessine-and-oganesson/ Atomic weight data 20160101 20160608 NA IUPAC Naming Four New Elements To determine findings NA 2016 Spatial Domain data includes all of the Earth, and should not be needed. It is provided because USGS software may not work properly without spatial domain values. Point Intro Standard and conventional atomic weights 2016 abridged to four significant digits Producer defined Contents Name of worksheet Producer defined Name of worksheet Table 1 Standard and conventional atomic weights 2016 abridged to four significant digits Producer defined Atomic Number Atomic number of the chemical element International Union of Pure and Applied Chemistry: https://iupac.org/ 1 118 Element Name IUPAC name of the chemical element in English International Union of Pure and Applied Chemistry: https://iupac.org/ Names of the elements International Union for Pure and Applied Chemistry: https://iupac.org/ Symbol Symbol of the chemical element International Union for Pure and Applied Chemistry: https://iupac.org/ Symbols of the chemical elements International Union for Pure and Applied Chemistry: https://iupac.org/ Standard Atomic Weight The 2016 four-digit standard atomic weight International Union for Pure and Applied Chemistry: https://iupac.org/ 1.007 238 Conventional Atomic Weight The conventional atomic weight provided to four digits for the 12 elements having interval atomic weight values, namely hydrogen, lithium, boron, carbon, nitrogen, oxygen, magnesium, silicon, sulfur, chlorine, bromine, and thallium International Union for Pure and Applied Chemistry: https://iupac.org/ 1.008 204.4 ScienceBase U.S. Geological Survey - ScienceBase mailing and physical

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Denver CO 80225 USA 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Word docx document and text file Microsoft Word 2007 http://dx.doi.org/10.5066/F79Z9315 None. No fees are applicable for obtaining the data set. 20220908 GS-W-VAres BRR Isotopes U.S. Geological Survey Director, Reston Stable Isotope Laboratory mailing and physical

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Reston Virginia 20192 USA 703-648-5862 isotopes@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998