Other pages in this series (88)
Atomic weight
Ar · argon
아르곤
Takeaway
- Recommended or revised 9 times between 1902 and 2024 (first record 1902, latest revision 2017).
- The one revision whose previous recommendation had an uncertainty kept the new value inside the previous (expanded) range.
- Since 2017, it has been given as the interval [39.792, 39.963] rather than a single value (the range found in normal materials).
| 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 | 39.9 | no uncertainty | O=16 | 39.89850375 | 10.1007/BF01370337 | |
| 1911 | 39.88 | no uncertainty | O=16 | 39.8785045 | 10.1021/ja01928a001 | |
| 1920 | 39.9 | no uncertainty | O=16 | 39.89850375 | 10.1021/ja02233a600 | |
| 1925 | 39.91 | no uncertainty | O=16 | 39.90850338 | 10.1039/CT9252700913 | |
| 1931 | 39.944 | no uncertainty | O=16 | 39.9425021 | 10.1039/JR9310001617 | |
| 1961 | 39.948 | no uncertainty | 12C=12 | 39.948 | 10.1021/ja00881a001 | |
| 1969 | 39.948(3) | value(uncertainty) | 12C=12 | 39.948 | 10.1351/pac197021010091 | |
| 1979 | 39.948(1) | value(uncertainty) | 12C=12 | 39.948 | 0.000 | 10.1351/pac198052102349 |
| 2017 | [39.792, 39.963] | interval | 12C=12 | 39.8775 (interval midpoint, for calculation) | 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