Radioactivity and Radiochemistry

In addition to the common stable form, P, (naturally 100% abundant species) there are at least six unstable isotopic forms of phosphorus. These isotopes have atomic weights, half-lives and decay emissions as indicated in Table 13.13. Other short-lived species reported include P, P and P to P. 

The radiochemistry of phosphorus is concerned with the chemical and nuclear behaviour of these isotopes. This can be distinguished from the radiation chemistry of phosphorus which is concerned with the effects of high-energy particles or radiation on the compounds of phosphorus (usually P compounds). 

Visible and ultra violet radiation are generally capable only of causing bond dissociation and are traditionally associated with photochemistry (Table 13.14). The more energetic x-rays or y-rays interact with atoms to give more x-rays (of lower frequency) and slowed-down electrons, which can cause ionisation or be captured by molecules. This in turn influences their physical and chemical behaviour and 

The bombardment of compounds with neutrons or a particles causes major changes in the nature of the atomic nucleus and such effects are utilised in the preparation of unstable isotopes. 

The development of nuclear reactors over the past 50 years has led to low-cost availability of the isotope and it has achieved considerable importance in radiochemical, biological and medical work. The isotope can be easily produced, it has a convenient half-life and has an energetic p emission. 

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S. deFilippis, Activity Analysis in Liquid Scintillation Counting, in Radioactivity and Radiochemistry 1, 4, 22 (1990)... 

Journals such as Radio chemistry. Radioactivity and Radiochemistry, and the Journal of Radioanalytical and Nuclear Chemistry currently are vehicles for publishing radioanalytical chemistry methods. Groups such as the American Society for Testing and Materials (ASTM) and the American Public Health Association (APHA) publish standard methods for radiochemistry (see Section 6.5), among other topics. 

McDowell, W. J. 1992. Photon/electron-rejecting alpha liquid scintillation (PERALS) spectrometry. A review. Radioactivity and Radiochemistry 3, 26-53. 

Figure 11,8 Composite decay curves for (A) mixtures of independently decaying species, (B) transient equilibrium, (C) secular equilibrium, and (D) nonequilibrium, a composite decay curve b decay curve of longer-lived component (A) and parent radio nuclide (B, C, D) c decay curve of short-lived radionuclide (A) and daughter radionuclide (B, C, D) d daughter radioativity in a pure parent fraction (B, C, D) e total daughter radioactivity in a parent-plus-daughter fraction (B). In all cases, the detection coefficients of the various species are assumed to be identical. From Nuclear and Radiochemistry, G. Friedlander and J. W. Kennedy, Copyright 1956 by John Wiley and Sons. Reprinted by permission of John Wiley and Sons Ltd.

One term that is frequently associated with nuclear chemistry is that of radiochemistry. The term radiochemistry refers to the chemical manipulation of radioactivity and associated phenomena. All radiochemists are, by definition, nuclear chemists, but not all nuclear chemists are radiochemists. Many nuclear chemists use purely nonchemical, that is, physical techniques, to study nuclear phenomena, and thus their work is not radiochemistry. 

Keller, C. Radiochemistry, Harwood, 1981. A very condensed presentation of radioactivity and its applications. 

One of the most important applications of nuclear and radiochemistry is in the area of nuclear power. Chemistry and chemical processes are intimately involved in reactor operation, the preparation and processing of reactor fuel, and the storage and ultimate disposal of radioactive waste. In this chapter, we shall examine some of the most important chemistry associated with nuclear power. 

This tiny quantity of material, if prepared as an aqueous solution of volume 1 L, would have a concentration of 10 14 mol/L. This simple calculation demonstrates a number of the important features of radiochemistry, that is, (a) the manipulation of samples involving infinitesimal quantities of material, (b) the power of nuclear analytical techniques (since 1 j.Ci is a significant, easily detectable quantity of radioactivity), and (c) in an extension of the calculation, since the decay of a single atom might occur by a-particle emission (with 100% detection efficiency), the ability to do chemistry one atom at a time. 

Most scientists involved in radioactive research had a background in chemistry or physics, and up to World War I little distinction was made between the physical and chemical aspects of radioactive research. As Ruth Sime points out, radioactivity split after the war. In 1917, to give an example, the radioactive section at the Kaiser-Wilhelm-Institut fur Chemie in Berlin-Dahlem split into a physical section (headed by Meitner) and a chemical section (headed by Hahn). In some sense, however, the field retained its unity radiochemistry was kept much alive at the Institut du Radium in Paris, and this expertise helped in the discovery of artificial radioactivity, when phosphorus had to be isolated in three minutes. The subdisciplinary divide was informed by a common interest in radioactive substances. This division did not so much reflect the independence of radiophysics and radiochemistry, as the mutual confidence of their practitioners. As Sime puts it Physicists and chemists collaborated across a pronounced disciplinary divide... they trusted each other s expertise without always understanding each other s limitations . 

J. P. Adloff, P. P. Gaspar, M. Imamura, A. G. Maddock, T. Matsuura, H. Sano, K. Yoshihara (Eds.), Handbook of Hot Atom Chemistry, Kodansha, Tokyo, and VCH Verlag, Weinheim, 1992 J. P. Adloff, R. Guillaumont, Frmdamentals of Radiochemistry, CRC Press, Boca Raton, FL, 1993 A. G. Maddock, Radioactivity and the Nuclear Environment, Radiochim. Acta 70171, 323 (1995)... 

The book is mainly addressed to chemists desiring sound information about this branch of chemistry dealing with the properties of radioactive matter. Students and scientists working in other branches of chemistry, in enviromental science, physics, geology, mineralogy, biology, medicine, technology and other fields will also find valuable information about the principles and applications of nuclear and radiochemistry. 

Research in nuclear and radiochemistry comprises Study of radioactive matter in nature, investigation of radioactive transmutations and of nuclear reactions by chemical methods, hot atom chemistry (chemical effects of nuclear reactions) and influence of chemical bonding on nuclear properties, production of radionuclides and labelled compounds, and the chemistry of radioelements - which represent more than a quarter of all chemical elements. 

Chemistry Video Consortium, Practical Laboratory Chemistry, Educational Media Film and Video Ltd, Harrow, Essex, UK - Polarimetry, refractometry and radiochemistry (using a polarimeter, determining the refraetive indiees of liquids, measuring the rates of radioactive processes and measuring gas phase emission spectra). 

Nuclear and radiochemistry deals with radioactive substances—from fundamental studies of atomic nuclei and chemical properties of radioactive elements to practical applications of radioactivity and nuclear technology. 

Nuclear and radiochemistry includes accelerator/reactor chemistry for isotope production, nuclear structure, neutrino chemistry, nuclear forensics, and archeometery. Understanding of nuclear and radiochemistry underlies the availability of adequate supplies as well as proper and safe use of radioactivity for energy production or radiomedicine. Twenty percent of electric power in the United States is supplied by nuclear reactors. It is possible that construction of new reactors in the United States will resume within the next decade. Similarly, the use of radionuclides in medicine, research, and industry is predicted to increase. 

As you study this chapter, the contributions of Mme. Curie, Pierre Curie, and the others of that time will become even more clear. Ironically, the field of medicine has been a major beneficiary of advances in nuclear and radiochemistry, despite the toxic properties of those same radioactive materials. 

Until 1934, only naturally occurring radioactive elements were available for study. However, in January of that year, Irene Curie (daughter of Marie Curie) and Frederic Joliot reported that boron and aluminum samples were made radioactive by bombarding them with a-particles from polonium to produce the two new radioactive products, and respectively. This discovery established the new fields of nuclear chemistry and radiochemistry and sparked their rapid growth. 

Friedlander, G., J. W. Kennedy and J. M. Miller, Nuclear and Radiochemistry, 2ndedn., Wiley, New York, 1964 (discussion of radioactivity and nuclear stability). 

Brandel, V., Dacheux, N., Genet, M., Studies on the chemistry of uranium and thorium phosphates. Thorium phosphate diphosphate A matrix for storage of radioactive wastes. Radiochemistry (Moscow), 43, (2001), D-22. Cited on pages 325, 663. 

The subject of this book has it roots in chemistry and in nuclear science. Since every chemical element can be made radioactive and followed through chemical reactions by means of this property, radiochemistry has contributed to most areas of chemistry. Nuclear chemistry - according to a definition by Ernst Rutherford - includes all changes in elemental composition by nuclear reactions. 

We simply define radiochemistry and nuclear chemistry by the content of this book, which is primarily written for chemists. The content contains fimdamental chapters followed by those devoted to applications. Each chapter ends with a section of exercises (with answers) and literature references. An historic introduction (Ch. 1) leads to chapters on stable isotopes and isotope separation, on unstable isotopes and radioactivity, and on radionuclides in nature (Ch. 2-5). Nuclear radiation - emission, absorbance, chemical effects radiation chemistry), detection and uses - is covered in four chapters (Ch. 6-9). This is followed by several chapters on elementary particles, nuclear structure, nuclear reactions and the production of new atoms (radio-nuclides of known elements as well as the transuranium ones) in the laboratory and in cosmos (Ch. 10-17). Before the four final chapters on nuclear energy and its environmental effects (Ch. 19-22), we have inserted a chapter on radiation biology and radiation protection (Ch. 18). Chapter 18 thus ends the fimdam tal part of radiochemistry it is essential to all students who want to use radionuclides in scientific research. By this arrangement, the book is subdivided into 3 parts fundamental ladiochemistry, nuclear reactions, and applied nuclear energy. We hope that this shall satisfy teachers with differrat educational goals. 

The section Radioactive Methods in volume 9 of the Treatise on Analytical Chemistry (Kolthoff and Elving 1971) discusses radioactive decay, radiation detection, tracer techniques, and activation analysis. It has a brief but informative chapter on radiochemical separations. A more recent text. Nuclear and Radiochemistry Fundamentals and Applications (Lieser 2001), discusses radioelements, decay, counting instruments, nuclear reactions, radioisotope production, and activation analysis in detail. It includes a brief chapter on the chemistry of radionuclides and a few pages on the properties of the actinides and transactinides. 

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