Standard atomic weights of the elements 2021 (IUPAC Technical Report)
نویسندگان
چکیده
Abstract Following the reviews of atomic-weight determinations and other cognate data in 2015, 2017, 2019 2021, IUPAC (International Union Pure Applied Chemistry) Commission on Isotopic Abundances Atomic Weights (CIAAW) reports changes standard atomic weights. The symbol A r °(E) was selected for weight an element to distinguish it from E a specific substance P, designated (E, P). CIAAW has changed values weights five elements based recent terrestrial isotopic abundances: Ar (argon): 39.948 ± 0.001 [39.792, 39.963] Hf (hafnium): 178.49 0.02 178.486 0.006 Ir (iridium): 192.217 0.003 0.002 Pb (lead): 207.2 0.1 [206.14, 207.94] Yb (ytterbium): 173.054 0.005 173.045 0.010 argon lead have interval reflect that natural variation composition exceeds measurement uncertainty (Ar) (Pb) substance. and/or uncertainties fourteen been Mass Evaluations 2016 2020 accomplished under auspices International Physics (IUPAP). ° Ho, Tb, Tm Y were 2017 again updated 2021: Al (aluminium), 2017: 26.981 5385 0.000 0007 5384 0003 Au (gold), 196.966 569 005 570 004 Co (cobalt), 58.933 194 003 F (fluorine), 18.998 403 163 000 006 162 (Ho (holmium), 164.930 33 02 328 007) Ho 007 329 Mn (manganese), 54.938 044 043 002 Nb (niobium), 92.906 37 01 Pa (protactinium), 231.035 88 Pr (praseodymium), 140.907 66 Rh (rhodium), 102.905 50 49 Sc (scandium), 44.955 908 907 (Tb (terbium), 158.925 35 354 008) Tb 008 (Tm (thulium), 168.934 22 218 006) 219 (Y (yttrium), 88.905 84 01) 838
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ژورنال
عنوان ژورنال: Pure and Applied Chemistry
سال: 2022
ISSN: ['0033-4545', '1365-3075']
DOI: https://doi.org/10.1515/pac-2019-0603