SYMPOSIUM
Introduction W i t h i n the past few years, it has become necessary to introduce radiochemistry and nuclear chemistry into an already crowded curriculum. Material has been developed a t all levels from the general course to graduate work. This symposium was organized to share the experience of some of the leaders in the field in presenting this material a t all of these levels. The problem is essentially twofold: first, how to present radioactivity and nuclear chemistry in an iuteresting manner to the large numbers of undergraduate students, and, second, how to prepare our graduate students for research in this new field. There is general agreement that efforts must be continued in both these areas. THIS JOURNAL has published many articles pertinent
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to this subject. Thirty-six of them have been reprinted in a volume distributed gratis by Nuclear-Chicago Corporation, Des Plaines, Illinois. This symposium' goes beyond that volume in covering all aspects of the subject. The introductory paper, by Charles D. Coryell, of the Massachusetts Institute of Technology, included the historical development and an emphatic delineation of the importance of the subject. The abstract of his paper, entitled "The Radioactivation of Chemists," follows: The history of the development of nuclear ohemistry represents the commonest attribute of the field which is tau& here and 1 A symposium presented before the Division of Chemical Education at the 136th Meeting of the American Chemical Society, Atlantic City, N. J., September, 1959.
there in contemporaneous chemi~trycurricula. Its development was largely due to the interest. and imagination of physicists, and its exploitation far chemistry was largely the result of the exhaustive demands on nuclear chemistry made by physicists and engineers in 194145 for the bomb snd by nuclear engineers in the last decade for the development of militamand civilian "atomic" Dower. Let i s define nuclear chemi& in broad terms as the chemical aspects of nuclear transformation, the separation and study of nuclear species (stable or radioactive), radioactive decay, the effects of radiation on materials, and the use of nuclides in chemical research. Such a definition is tantamount to saying nuclear chemistry is what nuclear chemists do. Nobel priaes
07 k a h n , and G. T: Seaborg. Most of the teaching of the subject is based an the work of these, and of the Nobelist geneticist H. J. Muller and the physicists A. H. Becquerel, P. Curie, J. Chaddwick, E. Fermi, and E. 0. Lawrence. I t is probable that particle physics and physics techniques (many mare Nobelists) will furnish only a nebulous background, although the proliferation of huge eleotronuclear machinee in the Bev (100 ev) range brings operations closer to direct chemical importance, making a "ehemistry of thenucleus." The extension of the periodic system is central to chemical education. I n the known span of elements from 0 (the neutron, 1934) to element 102 (1958), the last ten are accessible as a result of transmutation in nuclear reactors (piles or bombs). Classical nuclear chemistry proved the importance of radiochemistry for uranium and thorium and provided impetus and techniques for the study of the transitory elements: polonium, radon (emanstion), francium, radium, actinium, and protactinium. Cyelotrons and reactors give working quantities of technetium, pramethium, and astatine. Thus trcmsmutation and radioactive decay are the key to 22 elements. But all the other 81 elements have radioactive isotopes useful for their analysis and for the study of their chemical properties. One synthetic element is beine manufactured on the ton scale. The role of uranium-233. urank~m-235,and plutonium-239 in the power industry today emphasizes the importance of nuclear chemistry in the modern curriculum. The number of stable nuclear speoies is about 272, and the number of naturally occurring long-lived ones u-hich have persisted since the crestion of matter is about 12, three in the heavy element region carrying in steady state about 40 radioactive descendents. The number of man-made radionuclides is about 1100. All hut a few of the elements have long-lived isotopes convenient for traoer studies. The work in physiology and medicine with tracers such as hydrogen-3, carbon-14, sodium24, phosphorus-32, sulfur-35, and iodine-131 has already saved more human lives than the two wartime atomic bombs destroyed. Isotope separations on the gram scale have been made for all elements with more than one natural representative, and separations on the kilogram or ton scale are made for some (hydrogen, lithium, baron, nitrogen, oxygen, and uranium). Another very large field is radiation chemistry, with its very important sister field, radiobiology. The importance of thermonuclear reactions brings in stellar chemistry as a dramatic new field, and the work of nuclear chemists with radiochemical dating opens new fields in geology and the chemistry of the formation of the sun, the planets, the meteorites, and the comets. The importance of nuclear chemistry for teaching today cannot be underestimated. F. ~ d d d y ,H. C. Urey, G. C. de Hevesy,
A. B. Garrett of Ohio State discussed his successful work with freshmen. Robert H. Maybury, the University of Redlands, showed how undergraduates can do tracer experiments with minimum equipment and expense. His views have already been published in THIS JOURNAL.% More advanced work was described bv K. S. Vorres of the State University of Iowa and L. L. Quill of Michigan State, while A. F. Scott treated the very successful program inaugurated by him at Reed College.
John E. Willard of the University of Wisconsin then told about the graduate work in the nuclear field a t his institution. He intends to publish this in detail later. Meanwhile, an abstract is presented here. The phrase "nuclear chemistry and radiochemistry," as commonly used, encompasses interests ranging from those of the nuclear physicist interested in the systematics of nuclear transmutation and decay to the organic chemist who wishes t o trace a reaction step with the aid of radiocarbon labeling. So a "nuclear" or "radiochemist" mav be either s nhvsieist with a
nuclear theory, counting techniques, chemical methods for the separation of the fission products, isotopes effects, and study of reaction mechanisms with the aid of tracers. As no student can become an authority in all fields, such courses are valuable nrimarilv for students olannine to snecialize in the areas concerned. No department can provide course work in every possible specialty. The most important training which graduate work can give a student is training in solving research-type problems as he meets them, a perspective on where to go for .the information, techniques necessary for such solutions, and a self-confidence in his ability to come to correct solutions. This paper describes a course designed to give students an intellieent ners~ectiveon the nrenaration. nraoerties. and uses
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an average enrollment of 70 graduate students from ten academic departments. The mutual interests of the members of this varied group include the following: all may sometime want to employ radioactive tracers in their research; all need to be able to appraise critically literature reports of experiments using tracer techniques; all are scientists expected hy their fellow citizens to be able to make an educated appraisal of newspaper reports on nuolear matters; and all me subject to radiation from fallout and the possibility of nuclear warfare. The course is given by s. physical chemist whose research is in the fields of chemical e'feets of nuclear transformations and radiation chemistry; i t has visiting lecturers who are specialists in biachemioal applications of tracers, medical applications of tracers, stable isotope tracers, and nuclear engineering. It follows no textbook but provides a 10;page bibliography of texts and references dealing with d l types of nuclear applications. There is no laboratory work, but equipment is demonstrated in lectures, in tours to campus laboratories, and by discussion of descriptions of instruments in catalogues of commercial instrument companies. Sets of practice problems emphasiee the Use of fundamental nrincinles and loeical thinkinn- t o obtain answers needed in prae~icalsfituations. I n addition to courses, any large graduate school has scores of graduate students employing radioactive tracers on thesis problems. Some examples of the value of such on-the-joh experience are given. Comments are made on the value of the use of the facilities of the national laboratories for courses and as a supplement to university facilities for reeesrrh.
The last paper in the symposium deals with S. T. Zencbelsky's successful course of a different nature at Rutgers. It is evident that the fundamentals of nuclear chemistry and radioactivity should be and have been successfully integrated into the freshmen course, while additional material can be provided in later courses. More and more graduate students are being trained for research in an expanding field. Some of the most successful of the many pioneers share their experience in the papers of this symposium. Earl W. Phelon, chairman of symposium Argonne National Laboratory, Argonne, Illinois Volume 37, Number 8, August 1960
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