THE ATOMIC WEIGHTS COMMISSION AND ISOTOPIC ABUNDANCE RATIO DETERMINATIONS.

Conference · Sun Aug 07 04:00:00 EDT 2005

OSTI ID:15020056

HOLDEN, N E

Following Thomson's discovery of stable isotopes in non-radioactive chemical elements, the derivation of atomic weight values from mass spectrometric measurements of isotopic abundance ratios moved very slowly. Forty years later, only 3 1/2 % of the recommended values were based on mass spectrometric measurements and only 38% in the first half century. It might be noted that two chemical elements (tellurium and mercury) are still based on chemical measurements, where the atomic weight value calculated from the relative isotopic abundance measurement either agrees with the value from the chemical measurement or the atomic weight value calculated from the relative isotopic abundance measurement falls within the uncertainty of the chemical measurement of the atomic weight. Of the 19 chemical elements, whose atomic weight is based on non-corrected relative isotopic abundance measurements, five of these are two isotope systems (indium, iridium, lanthanum, lutetium and tantalum) and one is a three-isotope system (oxygen).

• Research Organization: BROOKHAVEN NATIONAL LABORATORY
• Sponsoring Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 15020056
• Report Number(s): BNL--74881-2005-CP; KB0301041
• Country of Publication: United States
• Language: BNL/SC

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ABUNDANCE
INDIUM
IRIDIUM
LANTHANUM
LUTETIUM
MASS NUMBER
MERCURY
OXYGEN
PERIODIC SYSTEM
STABLE ISOTOPES
TANTALUM
TELLURIUM