Standard Atomic Weight Values for the Mononuclidic Elements: 2001.

Holden, N. E.

Technical Information Center Oak Ridge Tennessee

关键词: Atomic mass;    Isotopes;    Standards;    Tables(Data);    Oxygen isotopes;   

RP-ID  :  DE2001782053

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Atomic Mass Evaluations have had a major impact on the values of the atomic weights for the twenty mononuclidic elements plus two elements, Thorium and Protactinium, which have no stable nuclides but a characteristic terrestrial isotopic composition. This paper reviews the history of the atomic weight values of these elements in the years, since the reference mass standard changed from (sup 16 O) to (sup 12 C). There is a problem for Thorium, which is considered to have an abundance value of 100%, but is not treated as such in the Standard Atomic Weights Table. Recommendations for handling the Standard Atomic Weight values for 2001 are presented.