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Atomic Weights of 10 Elements on Periodic Table to Change
- gus_massa 16y agoThe article has error or at least it is misleading. Short version: * ~1815-~1960 they use the H=1 or O=16 scales. They are two different scales, some people preferred one and other people preferred the otter one. In one of them H has "weight" 1 and in the other O has "weight" 16. * From ~1960 they use the C_12=12 scale. This is another scale, where the isotope 12 of carbon has "weight" 12. * There are a lot of technical modifications and, corrections during these 200 ~years. This a simplification of the history. Also, from 1951 the atomic weights of some elements have uncertainties. Based on a report by Marble 98 , a range was finally added to the atomic weight value of sulfur for the first time in the 1951 report 99 . In the 1961 report 65 , ranges were listed for six elements due to the natural variation in their isotopic composition and experimental uncertainties were added for five other elements following a systematic review by Cameron and Wichers. So in the last 100 years there has been a lot of changes, a los of codifications and a atomic weight had uncertainties. Apparently this will only be a new way to show the uncertainties. Looong version: http://www.iupac.org/publications/ci/2004/2601/1_holden.html http://www.iupac.org/publications/ci/2004/2601/1_holden.html