Editing Relative atomic mass (section)

== Standard atomic weight ==
{{main|Standard atomic weight}}

The [[IUPAC]] commission [[CIAAW]] maintains an expectation-interval value for relative atomic mass (or atomic weight) on Earth named standard atomic weight. Standard atomic weight requires the sources be terrestrial, natural, and stable with regard to radioactivity. Also, there are requirements for the research process. For 84 stable elements, CIAAW has determined this standard atomic weight. These values are widely published and referred to loosely as 'the' atomic weight of elements for real-life substances like pharmaceuticals and commercial trade. 

Also, CIAAW has published abridged (rounded) values and simplified values (for when the Earthly sources vary systematically).