Zr · zirconium

지르코늄

Takeaway

Recommended or revised 7 times between 1902 and 2024 (first record 1902, latest revision 2024).
Both revisions whose previous recommendation had an uncertainty kept the new value inside the previous (expanded) range.
The current standard atomic weight is 91.222(3) (recommended in 2024).

Relative deviation from the current (or last) value, symmetric-log axis. Bars: uncertainty (expanded range); open circles: no uncertainty; orange boxes: intervals.

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	90.7	no uncertainty	O=16	90.69659875		10.1007/BF01370337
1903	90.6	no uncertainty	O=16	90.5966025		10.1021/ja02003a001
1925	91	no uncertainty	O=16	90.9965875		10.1039/CT9252700913
1931	91.22	no uncertainty	O=16	91.21657925		10.1039/JR9310001617
1969	91.22(1)	value(uncertainty)	12C=12	91.22		10.1351/pac197021010091
1983	91.224(2)	value(uncertainty)	12C=12	91.224	0.400	10.1351/pac198456060653
2024	91.222(3)	value(uncertainty)	12C=12	91.222	−1.000	no DOI

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