Sm · samarium

사마륨

Takeaway

Recommended or revised 8 times between 1902 and 2024 (first record 1902, latest revision 2005).
Both revisions whose previous recommendation had an uncertainty kept the new value inside the previous (expanded) range.
The current standard atomic weight is 150.36(2) (recommended in 2005).

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	150	no uncertainty	O=16	149.994375		10.1007/BF01370337
1905	150.3	no uncertainty	O=16	150.29436375		10.1021/ja01979a001
1909	150.4	no uncertainty	O=16	150.39436		10.1021/ja01931a001
1925	150.43	no uncertainty	O=16	150.42435888		10.1039/CT9252700913
1955	150.35	no uncertainty	O=16	150.34436188		10.1021/ja01595a001
1969	150.4(1)	value(uncertainty)	12C=12	150.4		10.1351/pac197021010091
1979	150.36(3)	value(uncertainty)	12C=12	150.36	−0.400	10.1351/pac198052102349
2005	150.36(2)	value(uncertainty)	12C=12	150.36	0.000	10.1351/pac200678112051

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