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Atomic weight
Ir · iridium
이리듐
Takeaway
- Recommended or revised 6 times between 1902 and 2024 (first record 1902, latest revision 2017).
- Both revisions whose previous recommendation had an uncertainty kept the new value inside the previous (expanded) range.
- The current standard atomic weight is 192.217(2) (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 | 193.0 | no uncertainty | O=16 | 192.9927625 | 10.1007/BF01370337 | |
| 1909 | 193.1 | no uncertainty | O=16 | 193.09275875 | 10.1021/ja01931a001 | |
| 1953 | 192.2 | no uncertainty | O=16 | 192.1927925 | 10.1039/JR9540004713 | |
| 1969 | 192.22(3) | value(uncertainty) | 12C=12 | 192.22 | 10.1351/pac197021010091 | |
| 1993 | 192.217(3) | value(uncertainty) | 12C=12 | 192.217 | −0.100 | 10.1351/pac199466122423 |
| 2017 | 192.217(2) | value(uncertainty) | 12C=12 | 192.217 | 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