Great article-very interesting and informative. There is however an error that I would like to see corrected. The articles states "its atomic mass (the number of protons plus neutrons)". The number of protons plus neutrons is the 'mass number'; the mass of a single atom express in atomic mass units is the 'atomic mass'; the average of the atomic masses of the naturally occurring isotopes of an element is the 'average atomic mass' or the 'atomic weight'. The distinction between mass number, atomic mass, and atomic weight has tripped up many chemistry students.
posted by Jim Mehls
January 5, 2013
About once a month at Sigma Xi headquarters, we liven up the lunch hour with an American Scientist Pizza Lunch talk. In these informal lectures, scientists describe new research to nonscientists. The series is light on jargon but heavy on solid science. Each Pizza Lunch offers an in-depth look at its subject, whether it's bedbugs or the smart grid. Click below to read about and download these talks -- and to subscribe!
JSTOR, the online academic archive, now contains complete back issues of American Scientist from its inception in 1913 (as Sigma Xi Quarterly) through 2005.
The table of contents for each issue is freely available to all users; those with institutional access can read each complete issue.
View the full collection here.