Term: relative molecular mass, \(M_{\text{r}}\)
https://doi.org/10.1351/goldbook.R05271

Definition:
Ratio of the mass of a molecule to the unified atomic mass unit. Sometimes called the molecular weight or relative molar mass.

Related Terms:
1) unified atomic mass unit (http://doi.org/10.1351/goldbook.U06554).
2) relative molar mass (http://doi.org/10.1351/goldbook.R05270).
3) molecular weight (http://doi.org/10.1351/goldbook.M04000).

Source: Green Book, 2nd ed., p. 41 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)

Citation: 'relative molecular mass, \(M_{\text{r}}\)' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.R05271

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