Unified atomic mass unit

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IUPAC RECOMMENDATIONS 2013

K. K. Murray, R. K. Boyd, M. N. Eberlin, G. J. Langley, L. Li and Y. Naito, Pure Appl. Chem., 2013, 85, 1515-1609, 10.1351/PAC-REC-06-04-06.

Unified atomic mass unit , u
unified atomic mass unit, u

Dalton

Non-SI unit of mass defined as one-twelfth of the mass of one atom of 12C at rest in its ground state and equal to 1.660 538 921 (73) × 10-27 kg where the digits in parentheses indicate the estimated uncertainty in the final two digits of the value. Equivalent to the dalton (Da) unit.

Note: The abbreviation amu for atomic mass unit is deprecated; it has been used to denote atomic masses measured relative to a single atom of 16O, or to the isotope-averaged mass of an oxygen atom, or to a single atom of 12C.
Related Term(s):
Reference(s):

IUPAC. Compendium of Chemical Terminology, 2nd ed. (the “Gold Book”). Compiled by A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins.

P. J. Mohr, B. N. Taylor, D. B. Newell. Rev. Mod. Phys. 84, 1527 (2012). (http://dx.doi.org/10.1103/RevModPhys.84.1527 )

Definitions of Terms Relating to Mass Spectrometry (IUPAC Recommendations 2013); DOI: 10.1351/PAC-REC-06-04-06 © IUPAC 2013.


Index of Terms

 




Orange Book

ORANGE BOOK DEFINITION

IUPAC. Analytical Division. Compendium of Analytical Nomenclature (the “Orange Book”). Definitive Rules, 1979.

Unified atomic mass unit

This unit (u) is based on the standard that the mass of 12C is exactly 12 u. The older symbol, amu, using the standard based on the mass of 16O is no longer recommended. In biochemistry the term dalton, symbol Da, is sometimes used but is not here recommended.

IUPAC Orange Book Chapter 12
Index of Orange Book Terms


Gold Book

GOLD BOOK DEFINITION

IUPAC. Compendium of Chemical Terminology, 2nd ed. (the “Gold Book”). Compiled by A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997).

Unified atomic mass unit

unified atomic mass unit

Non-SI unit of mass (equal to the atomic mass constant), defined as one twelfth of the mass of a carbon-12 atom in its ground state and used to express masses of atomic particles, u &61; 1.660 5402(10) x 10-27 kg.

IUPAC

IUPAC Gold Book
Index of Gold Book Terms


See also

External links