Nd · neodymium

네오디뮴

Takeaway

Recommended or revised 6 times between 1902 and 2024 (first record 1902, latest revision 2005).
The one revision whose previous recommendation had an uncertainty kept the new value inside the previous (expanded) range.
The current standard atomic weight is 144.242(3) (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	143.6	no uncertainty	O=16	143.594615		10.1007/BF01370337
1909	144.3	no uncertainty	O=16	144.29458875		10.1021/ja01931a001
1925	144.27	no uncertainty	O=16	144.26458988		10.1039/CT9252700913
1961	144.24	no uncertainty	12C=12	144.24		10.1021/ja00881a001
1969	144.24(3)	value(uncertainty)	12C=12	144.24		10.1351/pac197021010091
2005	144.242(3)	value(uncertainty)	12C=12	144.242	0.067	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