Sc · scandium

스칸듐

Takeaway

Recommended or revised 12 times between 1902 and 2024 (first record 1902, latest revision 2021).
All 6 revisions whose previous recommendation had an uncertainty kept the new value inside the previous (expanded) range.
The current standard atomic weight is 44.955 907(4) (recommended in 2021).

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	44.1	no uncertainty	O=16	44.09834625		10.1007/BF01370337
1921	45.1	no uncertainty	O=16	45.09830875		10.1021/ja01454a600
1925	45.10	no uncertainty	O=16	45.09830875		10.1039/CT9252700913
1951	44.96	no uncertainty	O=16	44.958314		10.1039/JR9530000001
1961	44.956	no uncertainty	12C=12	44.956		10.1021/ja00881a001
1969	44.9559(1)	value(uncertainty)	12C=12	44.9559		10.1351/pac197021010091
1983	44.955 91(1)	value(uncertainty)	12C=12	44.95591	0.100	10.1351/pac198456060653
1985	44.955 910(9)	value(uncertainty)	12C=12	44.95591	0.000	10.1351/pac198658121677
1995	44.955 910(8)	value(uncertainty)	12C=12	44.95591	0.000	10.1351/pac199668122339
2005	44.955 912(6)	value(uncertainty)	12C=12	44.955912	0.250	10.1351/pac200678112051
2013	44.955 908(5)	value(uncertainty)	12C=12	44.955908	−0.667	10.1515/pac-2015-0305
2021	44.955 907(4)	value(uncertainty)	12C=12	44.955907	−0.200	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