Guidelines for the use of atomic weights

Provisional Recommendations are drafts of IUPAC recommendations on terminology, nomenclature, and symbols, made widely available to allow interested parties to comment before the recommendations are finally revised and published in IUPAC’s journal Pure and Applied Chemistry. 

Standard atomic weights are widely used in science, yet the uncertainties associated with these values are not well-understood. This recommendation provides guidance on the use of standard atomic weights and their uncertainties. Furthermore, methods are provided for calculating standard uncertainties of molecular weights of substances. Methods are also outlined to compute material-specific atomic weights whose associated uncertainty may be smaller than the uncertainty associated with the standard atomic weights.

Comments by 31 Aug 2016

See Provisional Recommendations currently under review.