Talk:Relative atomic mass
|WikiProject Measurement||(Rated C-class, Low-importance)|
|WikiProject Chemistry||(Rated C-class, Mid-importance)|
The article uses the notation of putting the uncertainty in parentheses, without explaining this notation. I came to the article while reading the articles on some elements hoping to find such an explanation.
The article links to Measurement uncertainty with a link label of "uncertainty", but there's no explanation there, either (I had guessed the notation was to do with uncertainty). In fact, there's an explanation in Uncertainty#Measurements. Isidore (talk) 13:16, 8 May 2013 (UTC)
Fix in lede
The lede says that relative atomic mass is used as a synonym for standard atomic weight and that really isn't right, unless it's incorrectly used. Relative atomic weight is the same as atomic weight, but it's the "standard" part of "standard atomic weight" that makes the terms potentially different. The "standard" refers to the source, and here it is:
Standard atomic weights are:
"Recommended values of relative atomic masses of the elements revised biennially by the IUPAC Commission on Atomic Weights and Isotopic Abundances and applicable to elements in any normal sample with a high level of confidence. A normal sample is any reasonably possible source of the element or its compounds in commerce for industry and science and has not been subject to significant modification of isotopic composition within a geologically brief period."
Values for relative atomic masses from deep rocks, meteorites, or geologically old stuff, won't be "standard". "Standard" means it's what you can expect from stuff on your chemical shelf, but the isotopica composition from an odd source can always fool you, and be out of standard rage. So the lede needs to be fixed.
All this is not helped by the fact that people often loosely use "atomic weight" to mean "standard atomic weight" (what you see on periodic tables and in WP articles on elements), and also that (probably for brevity's sake) the term "standard atomic relative mass" isn't used much, even though that's what this refers to, if you insist on using relative atomic mass. Add to that, that the term "relative atomic mass" is a lousy one, since it actually refers to an idea something like "isotope-weighted mean elemental atomic mass (on the C-12 scale)".
The section differentiating these terms needed some fixing and I found it residing in the atomic mass article, where it really didn't belong. I've improved it and moved it here. I'll fix up the lede to agree with it, and that will be a start on both these articles to get them at least minimally error-free. SBHarris 02:55, 9 May 2013 (UTC)
What garbage. What is historical about the current IUPAC recommendation?? Nothing. This section either needs complete rewrite or removal. Where is the discussion of the O-16 scale??????? And the standardization?> This is really embarrassing! If you have nothing to say, say nothing.188.8.131.52 (talk) 14:02, 28 August 2013 (UTC)
- We moved the O-16 stuff (pre-1961) to the article on unified atomic mass unit, where it belonged. The "unified" part of unified atomic mass unit is what differentiates C-12 based standardization from O-16 standardization, which was the basis of the (old) amu. Now, we have just the u, aka dalton, based on C-12). SBHarris 00:20, 10 October 2014 (UTC)
Confusion in the Table
The second paragraph points out that relative atomic mass is "technically different" from standard atomic weight. The third paragraph states that the table includes standard atomic weights, but the table's heading states that the numbers are relative atomic masses. Either the third paragraph, the table's heading, or the statement contrasting relative atomic masses and standard atomic weights needs to be corrected. HankW512 (talk) 16:44, 10 March 2014 (UTC)
Wouldn't it be better to use the goldbook template instead of the current links? For example: IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "mixing ratio". --RolfSander (talk) 07:07, 8 April 2014 (UTC)
Good non-terrestial examples
We need examples of Ar that are not naturally terrestial (i.e., are not used by CIAAW).
Potassium isotopic evidence for a high-energy giant impact origin of the Moon
Kun Wang & Stein B. Jacobsen Nature 538, 487–490 (27 October 2016) doi:10.1038/nature19341 Published online 12 September 2016