scholarly journals Standard Atomic Weight of Lead Revised

2021 ◽  
Vol 43 (3) ◽  
pp. 30-30
Keyword(s):  
Isotopic Composition ◽  
Atomic Weight ◽  
Atomic Mass ◽  
Lead Isotopic Composition ◽  
Technical Report ◽  
Relative Atomic Mass ◽  
Isotopic Abundances ◽  
Iupac Commission

Abstract Following the recent publication of the IUPAC Technical Report on the variation of lead isotopic composition and atomic weight in terrestrial materials [1], the IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW) is recommending changes to the standard atomic weight (i.e. relative atomic mass) of lead:

Atomic weights of the elements 1999 (IUPAC Technical Report)

2001 ◽  
Vol 73 (4) ◽  
pp. 667-683 ◽  
Author(s):  
Tyler B. Coplen
Keyword(s):  
Isotopic Composition ◽  
Scientific Community ◽  
Atomic Weight ◽  
Atomic Mass ◽  
Isotopic Abundance ◽  
Technical Report ◽  
Relative Atomic Mass ◽  
Isotopic Abundances

The biennial review of atomic-weight, Ar(E), determinations and other cognate data have resulted in changes for the standard atomic weights of the following elements: elementFromTonitrogen14.006 74 ± 0.000 0714.0067 ± 0.0002 sulfur32.066 ± 0.00632.065 ± 0.005 chlorine35.4527 ± 0.000935.453 ± 0.002germanium72.61 ± 0.0272.64 ± 0.01 xenon131.29 ± 0.02131.293 ± 0.006 erbium167.26 ± 0.03167.259 ± 0.003 uranium238.0289 ± 0.0001238.028 91 ± 0.000 03 Presented are updated tables of the standard atomic weights and their uncertainties estimated by combining experimental uncertainties and terrestrial variabilities. In addition, this report again contains an updated table of relative atomic-mass values and half-lives of selected radioisotopes. Changes in the evaluated isotopic abundance values from those published in 1997 are so minor that an updated list will not be published for the year 1999.Many elements have a different isotopic composition in some nonterrestrial materials. Some recent data on parent nuclides that might affect isotopic abundances or atomic-weight values are included in this report for the information of the interested scientific community.

scholarly journals Interpreting and propagating the uncertainty of the standard atomic weights (IUPAC Technical Report)

2018 ◽  
Vol 90 (2) ◽  
pp. 395-424 ◽  
Author(s):  
Antonio Possolo ◽  
Adriaan M. H. van der Veen ◽  
Juris Meija ◽  
D. Brynn Hibbert
Keyword(s):  
Probability Distribution ◽  
Isotopic Composition ◽  
Probability Distributions ◽  
Atomic Weight ◽  
Relative Molecular Mass ◽  
Detailed Knowledge ◽  
Technical Report ◽  
Other Information ◽  
Isotopic Abundances ◽  
Molecular Masses

AbstractIn 2009, the Commission on Isotopic Abundances and Atomic Weights (CIAAW) of the International Union of Pure and Applied Chemistry (IUPAC) introduced the interval notation to express the standard atomic weights of elements whose isotopic composition varies significantly in nature. However, it has become apparent that additional guidance would be helpful on how representative values should be derived from these intervals, and on how the associated uncertainty should be characterized and propagated to cognate quantities, such as relative molecular masses. The assignment of suitable probability distributions to the atomic weight intervals is consistent with the CIAAW’s goal of emphasizing the variability of the atomic weight values in nature. These distributions, however, are not intended to reflect the natural variability of the abundances of the different isotopes in the earth’s crust or in any other environment. Rather, they convey states of knowledge about the elemental composition of “normal” materials generally, or about specific classes of such materials. In the absence of detailed knowledge about the isotopic composition of a material, or when such details may safely be ignored, the probability distribution assigned to the standard atomic weight intervals may be taken as rectangular (or, uniform). This modeling choice is a reasonable and convenient default choice when a representative value of the atomic weight, and associated uncertainty, are needed in calculations involving atomic and relative molecular masses. When information about the provenance of the material, or other information about the isotopic composition needs to be taken into account, then this distribution may be non-uniform. We present several examples of how the probability distribution of an atomic weight or relative molecular mass may be characterized, and also how it may be used to evaluate the associated uncertainty.

scholarly journals Atomic weights of the elements 2013 (IUPAC Technical Report)

2016 ◽  
Vol 88 (3) ◽  
pp. 265-291 ◽  
Author(s):  
Juris Meija ◽  
Tyler B. Coplen ◽  
Michael Berglund ◽  
Willi A. Brand ◽  
Paul De Bièvre ◽  
...  
Keyword(s):  
Isotope Ratio ◽  
Atomic Weight ◽  
Atomic Mass ◽  
Uranium Isotope ◽  
List Type ◽  
Technical Report ◽  
Isotopic Abundances ◽  
Standard Value

AbstractThe biennial review of atomic-weight determinations and other cognate data has resulted in changes for the standard atomic weights of 19 elements. The standard atomic weights of four elements have been revised based on recent determinations of isotopic abundances in natural terrestrial materials: cadmium to 112.414(4) from 112.411(8),molybdenum to 95.95(1) from 95.96(2),selenium to 78.971(8) from 78.96(3), andthorium to 232.0377(4) from 232.038 06(2).The Commission on Isotopic Abundances and Atomic Weights (ciaaw.org) also revised the standard atomic weights of fifteen elements based on the 2012 Atomic Mass Evaluation: aluminium (aluminum) to 26.981 5385(7) from 26.981 5386(8),arsenic to 74.921 595(6) from 74.921 60(2),beryllium to 9.012 1831(5) from 9.012 182(3),caesium (cesium) to 132.905 451 96(6) from 132.905 4519(2),cobalt to 58.933 194(4) from 58.933 195(5),fluorine to 18.998 403 163(6) from 18.998 4032(5),gold to 196.966 569(5) from 196.966 569(4),holmium to 164.930 33(2) from 164.930 32(2),manganese to 54.938 044(3) from 54.938 045(5),niobium to 92.906 37(2) from 92.906 38(2),phosphorus to 30.973 761 998(5) from 30.973 762(2),praseodymium to 140.907 66(2) from 140.907 65(2),scandium to 44.955 908(5) from 44.955 912(6),thulium to 168.934 22(2) from 168.934 21(2), andyttrium to 88.905 84(2) from 88.905 85(2).The Commission also recommends the standard value for the natural terrestrial uranium isotope ratio, N(238U)/N(235U)=137.8(1).

Isotope-abundance variations of selected elements (IUPAC Technical Report)

2002 ◽  
Vol 74 (10) ◽  
pp. 1987-2017 ◽  
Author(s):  
Tyler B. Coplen ◽  
John Karl Böhlke ◽  
P. De Bièvre ◽  
T. Ding ◽  
N. E. Holden ◽  
...  
Keyword(s):  
Chemical Elements ◽  
Radioactive Decay ◽  
Atomic Weight ◽  
Chemical Fractionation ◽  
Isotope Abundance ◽  
Isotopic Compositions ◽  
Technical Report ◽  
Isotopic Abundances ◽  
Calcium Iron ◽  
Physical And Chemical

Documented variations in the isotopic compositions of some chemical elements are responsible for expanded uncertainties in the standard atomic weights published by the Commission on Atomic Weights and Isotopic Abundances of the International Union of Pure and Applied Chemistry. This report summarizes reported variations in the isotopic compositions of 20 elements that are due to physical and chemical fractionation processes (not due to radioactive decay) and their effects on the standard atomic-weight uncertainties. For 11 of those elements (hydrogen, lithium, boron, carbon, nitrogen, oxygen, silicon, sulfur, chlorine, copper, and selenium), standard atomic-weight uncertainties have been assigned values that are substantially larger than analytical uncertainties because of common isotope-abundance variations in materials of natural terrestrial origin. For 2 elements (chromium and thallium), recently reported isotope-abundance variations potentially are large enough to result in future expansion of their atomic-weight uncertainties. For 7 elements (magnesium, calcium, iron, zinc, molybdenum, palladium, and tellurium), documented isotope variations in materials of natural ter- restrial origin are too small to have a significant effect on their standard atomic-weight uncertainties. This compilation indicates the extent to which the atomic weight of an element in a given material may differ from the standard atomic weight of the element. For most elements given above, data are graphically illustrated by a diagram in which the materials are specified in the ordinate and the compositional ranges are plotted along the abscissa in scales of (1) atomic weight, (2) mole fraction of a selected isotope, and (3) delta value of a selected isotope ratio.

scholarly journals Isotopic compositions of the elements 2009 (IUPAC Technical Report)

2011 ◽  
Vol 83 (2) ◽  
pp. 397-410 ◽  
Author(s):  
Michael Berglund ◽  
Michael E. Wieser
Keyword(s):  
Mass Spectrometry ◽  
Isotope Ratio ◽  
Critical Evaluation ◽  
Isotope Ratio Mass Spectrometry ◽  
Atomic Weight ◽  
Single Sample ◽  
International Union ◽  
Isotopic Compositions ◽  
Technical Report ◽  
Isotopic Abundances

The Commission on Isotopic Abundances and Atomic Weights (CIAAW) of the International Union of Pure and Applied Chemistry (IUPAC) completed its last update of the isotopic compositions of the elements as determined by isotope-ratio mass spectrometry in 2009. That update involved a critical evaluation of the published literature and forms the basis of the table of the isotopic compositions of the elements (TICE) presented here. For each element, TICE includes evaluated data from the “best measurement” of the isotope abundances in a single sample, along with a set of representative isotope abundances and uncertainties that accommodate known variations in normal terrestrial materials. The representative isotope abundances and uncertainties generally are consistent with the standard atomic weight of the element Ar(E) and its uncertainty U[Ar(E)] recommended by CIAAW in 2007.

Clarification of the term “normal material” used for standard atomic weights (IUPAC Technical Report)

2018 ◽  
Vol 90 (7) ◽  
pp. 1221-1224 ◽  
Author(s):  
Tyler B. Coplen ◽  
Norman E. Holden ◽  
Michael E. Wieser ◽  
John Karl Böhlke
Keyword(s):  
Isotopic Composition ◽  
Nuclear Reactor ◽  
Isotopic Modification ◽  
Technical Report ◽  
Isotopic Abundances ◽  
Extraterrestrial Materials

Abstract The standard atomic weights of the elements apply to normal materials. Since 1984, the Commission on Isotopic Abundances and Atomic Weights (Commission) has defined a normal material as: “The material is a reasonably possible source for this element or its compounds in commerce, for industry or science; the material is not itself studied for some extraordinary anomaly and its isotopic composition has not been modified significantly in a geologically brief period.” The term “a geologically brief period” in this definition is confusing, and confusion can be reduced by revising this definition to the following, which was accepted by the Commission on Isotopic Abundances and Atomic Weights at its meeting in Groningen, Netherlands in September 2017: “Normal materials include all substances, except (1) those subjected to substantial deliberate, undisclosed, or inadvertent artificial isotopic modification, (2) extraterrestrial materials, and (3) isotopically anomalous specimens, such as natural nuclear reactor products from Oklo (Gabon) or other unique occurrences.”

scholarly journals Review of footnotes and annotations to the 1949–2013 tables of standard atomic weights and tables of isotopic compositions of the elements (IUPAC Technical Report)

2016 ◽  
Vol 88 (7) ◽  
pp. 689-699 ◽  
Author(s):  
Tyler B. Coplen ◽  
Norman E. Holden
Keyword(s):  
Isotopic Fractionation ◽  
Numerical Data ◽  
Atomic Weight ◽  
Current Standard ◽  
Additional Information ◽  
Isotopic Compositions ◽  
Technical Report ◽  
Isotopic Abundances ◽  
Terrestrial Material ◽  
A Current

Abstract The Commission on Isotopic Abundances and Atomic Weights uses annotations given in footnotes that are an integral part of the Tables of Standard Atomic Weights to alert users to the possibilities of quite extraordinary occurrences, as well as sources with abnormal atomic-weight values outside an otherwise acceptable range. The basic need for footnotes to the Standard Atomic Weights Table and equivalent annotations to the Table of Isotopic Compositions of the Elements arises from the necessity to provide users with information that is relevant to one or more elements, but that cannot be provided using numerical data in columns. Any desire to increase additional information conveyed by annotations to these Tables is tempered by the need to preserve a compact format and a style that can alert users, who would not be inclined to consult either the last full element-by-element review or the full text of a current Standard Atomic Weights of the Elements report. Since 1989, the footnotes of the Tables of Standard Atomic Weights and the annotations in column 5 of the Table of Isotopic Compositions of the Elements have been harmonized by use of three lowercase footnotes, “g”, “m”, and “r”, that signify geologically exceptionally specimens (“g”), modified isotopic compositions in material subjected to undisclosed or inadvertent isotopic fractionation (“m”), and the range in isotopic composition of normal terrestrial material prevents more precise atomic-weight value being given (“r”). As some elements are assigned intervals for their standard atomic-weight values (applies to 12 elements since 2009), footnotes “g” and “r” are no longer needed for these elements.

The isotopic composition and atomic weight of palladium

1978 ◽  
Vol 56 (10) ◽  
pp. 1333-1339 ◽  
Author(s):  
Masako Shima ◽  
C. E. Rees ◽  
H. G. Thode
Keyword(s):  
Mass Spectrometry ◽  
Isotopic Composition ◽  
Atomic Weight ◽  
Mass Discrimination ◽  
Source Mass ◽  
Isotopic Abundances ◽  
Artificial Mixtures

The isotopic composition of palladium was measured by solid source mass spectrometry. Artificial mixtures of separated palladium isotopes were prepared with accurately known isotopic composition and were used to determine the mass discrimination of the spectrometer. The corrected isotopic abundances give a revised value for the atomic weight of palladium of 106.415 ± 0.005 which is to be preferred to the currently accepted value of 106.4.

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