33 No. 2
From the Editor
The idea of changing something we take for granted can be a bit jarring, especially something as enduring and long-standing as the atomic weights on the periodic table. As the guardian of the internationally accepted values of atomic weights, the IUPAC Commission on Isotopic Abundances and Atomic Weights must continually assess these values and provide guidance on their usage.
At this time, the Commission’s assessment and review of published data, combined with the continuous improvement of analytical techniques available to the scientific community, are forcing a shift in the basic perception about atomic weights. Nowadays, measurement precision is such that in many cases the isotopic variation of certain elements, and not the uncertainties of the measurement, is what causes differences in atomic weight values. So, instead of hiding the concept of isotopes with an abstract number, the Commission now recommends providing the interval values for elements whose standard atomic weight is not constant.
It took about a century for the chemistry community to reach this point. There is no surprise in what the commission reveals; it is just the result of a process that has now reached a tipping point. Some might say “Why complicate things and render a basic concept more complex?” I think that a better way to view the situation is to consider this new development as an opportunity to explore or review concepts such as isotopes, or uncertainties, and to ask “What is ‘in’ these numbers?” Aside from presenting long tabulations, the Commission reports published in the February 2011 Pure and Applied Chemistry are full of details, footnotes, and annotations that together are quite enlightening. The feature by Ty Coplen and Norman Holden is an easier-to-read introduction to the formal reports.
In response to the Commission’s recommendations, a brand new updated periodic table has been compiled, which is provided here on the back cover. Yet another version with graphics similar to what is shown on the cover will be released very soon. An IUPAC task group chaired by Norman Holden is to provide the educational community with the tools and resources necessary to understand and adopt these recent changes.
The other feature in this issue offers a contrasting record of what concerns and interests chemists. Peter Atkins gives us a snapshot of the countless contributions of chemistry to the modern world in “Where Would We Be without Chemistry?” Perhaps this is too bold a question to fully answer, but chemists must not lose sight of the big picture. The International Year of Chemistry has given us an opportunity to talk to the world at large and Atkins reminds us to rightly celebrate the impact of chemistry and the ways in which it has transformed the world.
last modified 16 March 2011.
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