Vol.
27 No. 6
November-December 2005
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Standard Atomic Weights Revised
Following
its meeting, held 10-11 August 2005 at the 43rd IUPAC General
Assembly, the Commission
on Isotopic Abundances and Atomic Weights (II.1) released
the changes to the standard atomic weights of 16 chemical
elements. The following changes are based on new determinations
of isotopic abundances and reviews of previous isotopic abundances
and atomic masses:
|
From |
To |
Aluminium |
26.981 538 (2) |
26.981 5386 (8) |
Bismuth |
208.980 38 (2) |
208.980 40 (1) |
Caesium |
132.905 45 (2) |
132.905 4519 (2) |
Cobalt |
58.933 200 (9) |
58.933 195 (5) |
Gold |
196.966 55 (2) |
196.966 569 (4) |
Lanthanum |
138.9055 (2) |
138.905 47 (7) |
Manganese |
54.938 049 (9) |
54.938 045 (5) |
Neodymium |
144.24 (3) |
144.242 (3) |
Phosphorus |
30.973 761 (2) |
30.973 762 (2) |
Platinum |
195.078 (2) |
195.084 (9) |
Samarium |
150.36 (3) |
150.36 (2) |
Scandium |
44.955 910 (8) |
44.955 912 (6) |
Sodium |
22.989 770 (2) |
22.989 769 28 (2) |
Tantalum |
180.9479 (1) |
180.947 88 (2) |
Terbium |
158.925 34 (2) |
158.925 35 (2) |
Thorium |
232.0381 (1) |
232.038 06 (2) |
These
changes in the atomic weights will be published in a new Table
of Standard Atomic Weights 2005, which will be submitted for
publication in Pure and Applied Chemistry* by the
end of 2005. The commission also continued its review of publications
of variations in the natural isotopic abundances. The commission
also continued its review of publications of the variation
in the natural isotopic abundances. For more details about
the Commission meeting in Beijing, see Division
Roundups (in print on page 7).
For more
information, contact Michael E. Wieser <[email protected]>,
secretary of the IUPAC
Commission on Isotopic Abundances and Atomic Weights.
* IUPAC
Technical Report as Pure
Appl. Chem.
78(11), 2051-2066, 2006
Page
last modified 28 October 2005.
Copyright © 2003-2005 International Union of Pure and
Applied Chemistry.
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