View source for Molar mass constant

The '''molar mass constant''' (symbol: '''''M''<sub>u</sub>''') is a [[physical constant]] connecting [[atomic weight]] and [[molar mass]]. Under the 1972 definition of the [[mole]],<ref name="SI114-15">{{SIbrochure8th|pages=114–15}}.</ref> it has a defined value in [[SI units]] of {{nowrap|1&nbsp;g mol<sup>−1</sup>}}.<ref name="CODATA2006">{{CODATA 2006|url=http://physics.nist.gov/cgi-bin/cuu/Value?mu}}.</ref> Although it is not explicitly used in routine work, the constant is important for the formal coherence of the [[International System of Units]] (SI): it indicates where the factor of {{nowrap|10<sup>−3</sup>&nbsp;kg mol<sup>−1</sup>}} should appear in equations between [[Molar quantity|molar]] and [[Specific quantity|mass-based quantities]] and ensures that such equations need no additional numerical factor.<ref name="Milton&Mills">{{citation | title = Amount of substance and the proposed redefinition of the mole | first1 = M. J. T. | last1 = Milton | first2 = I. M. | last2 = Mills | journal = Metrologia | year = 2009 | volume = 46 | pages = 332–38 | doi = 10.1088/0026-1394/46/3/022}}.</ref>

==References==
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[[Category:Physical constants]]

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