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Atomic weight
Nb · niobium
나이오븀
Takeaway
- Recommended or revised 10 times between 1902 and 2024 (first record 1902, latest revision 2017).
- All 3 revisions whose previous recommendation had an uncertainty kept the new value inside the previous (expanded) range.
- The current standard atomic weight is 92.906 37(1) (recommended in 2017).
| Yearyear of the recommendation | Value (as printed)as printed in CIAAW's table; digits in parentheses are the uncertainty (expanded range) in the last digits | Notationvalue(uncertainty), interval or no uncertainty | Scalebefore 1961 oxygen = 16, from 1961 ¹²C = 12 | Value, ¹²C scalepre-1961 values multiplied by 15.9994/16 | z vs previous(new − previous) ÷ previous uncertainty | ReportDOI of the CIAAW report |
|---|---|---|---|---|---|---|
| 1902 | 94 | no uncertainty | O=16 | 93.996475 | 10.1007/BF01370337 | |
| 1909 | 93.5 | no uncertainty | O=16 | 93.49649375 | 10.1021/ja01931a001 | |
| 1917 | 93.1 | no uncertainty | O=16 | 93.09650875 | 10.1021/ja02268a001 | |
| 1931 | 93.3 | no uncertainty | O=16 | 93.29650125 | 10.1039/JR9310001617 | |
| 1935 | 92.91 | no uncertainty | O=16 | 92.90651588 | 10.1039/JR9350000788 | |
| 1961 | 92.906 | no uncertainty | 12C=12 | 92.906 | 10.1021/ja00881a001 | |
| 1969 | 92.9064(1) | value(uncertainty) | 12C=12 | 92.9064 | 10.1351/pac197021010091 | |
| 1985 | 92.906 38(2) | value(uncertainty) | 12C=12 | 92.90638 | −0.200 | 10.1351/pac198658121677 |
| 2013 | 92.906 37(2) | value(uncertainty) | 12C=12 | 92.90637 | −0.500 | 10.1515/pac-2015-0305 |
| 2017 | 92.906 37(1) | value(uncertainty) | 12C=12 | 92.90637 | 0.000 | 10.1515/pac-2019-0603 |
Source: Standard atomic weights © IUPAC/CIAAW 2016–2024. Commission on Isotopic Abundances and Atomic Weights, Historical changes of standard atomic weights (compiled by J. Meija), https://www.ciaaw.org/historical-atomic-weights.htm