REVIEWS


NUCLEAR SCIENCE A nuclear guide


‘Nuclear’ is a much-misused word. The use of the term in describing the centre of the atom seems to go back to Faraday. Chemists use it frequently in relation to nuclear magnetic resonance spectroscopy, biologists when talking of a cell. Yet the general public regards it as being synonymous with ‘radioactive’. It was Rutherford’s team that obtained the first experimental evidence for nuclear particles when firing a beam of α-particles at gold foil, finding that some were deflected massively, and observing that it was ‘almost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you.’ This was during the days when the Royal Navy was building battleships with 15-inch guns. Radioactivity had already been


detected by Henri Becquerel in 1896, and shown to be something different to the new X-rays. The subject moved from being a rather academic area in 1938, with the discovery of nuclear fission by Hahn and Meitner, to one with potential for either generating energy or as a weapon of war. Since then, we have been living with the consequences of the discoveries of that half-century of science, while the science behind it has continued to develop.


The Manhattan Project had


many spin-offs. Teflon (PTFE) had first been made in 1938, but found a niche as a fluorine-resistant material. Natural uranium contains


only 0.72% of the fissionable isotope 235


U so a way had to be found to


increase its concentration for use in an atom bomb. Gaseous diffusion was believed to be the best way of doing this, with Graham’s law predicting a difference in diffusion rate between 235


UF6 and 238 UF6 . Using


multiple stages for the process would result in an enrichment that would


afford a material with a sufficient 235


U concentration for a sustainable


fission process to occur. However, UF6 is so reactive that no material was known that could resist its attack, until PTFE was tried. The polymer was subsequently used in applications such as seals, valves and pipes. In addition, an important piece of chemistry was the preparation of very pure uranium compounds, since traces of impurities, such as B and Cd, could interfere with the chain reaction. Another fruit of the Manhattan Project was the separation of large amounts of lanthanides, by adsorbing them onto ion exchange resins, followed by elution using complexing agents like citrate. Previously, such pure lanthanides had only been available in tiny amounts, through tediously slow multistage fractional crystallisations – famously in 1911, Charles James used 15,000 stages to obtain pure thulium. After these original ion-exchange separations, superior complexing agents like EDTA were used and lanthanide coordination chemistry has now flourished. Such separation techniques were later applied to transuranium chemistry. This book is described as


an introductory text in nuclear


Author Peter A. C. McPherson


Publisher World Scientific


Pages 272 Price £40 ISBN 978-1786340511


Reviewer Simon Cotton is an honorary senior lecturer in chemistry at the University of Birmingham, UK


Principles of nuclear chemistry


chemistry and radiochemistry, aimed at undergraduates ‘with little or no knowledge of physics’ and scientists new to working in nuclear and radiochemistry. The content is thorough and inevitably goes beyond ‘chemistry’. The first chapter introduces the reader to essential physics concepts, starting with types of motion followed by electrostatics, quantum physics and particle physics. Successive chapters deal with atomic structure; nuclear structure; radioactive decay; nuclear reactions and particle accelerators; uses of radioactivity and exposure to radiation, together with its monitoring; spectroscopy and spectrometry of the nucleus; and applications of nuclear chemistry, including radiolabelling, nuclear medicine and nuclear power. The chemistry of the f-block elements is covered in some detail. All chapters conclude with useful review questions, and answers to the numerical ones are provided at the back of the book. It is harder to write a wide-ranging


book like this than a specialist textbook; conversely, it is easier for a reviewer to comment on their own specialist areas, as with odd incorrect statements like ‘the Ac(III) oxidation state dominates actinoid chemistry’, when a table on the same page (p219) shows the most stable oxidation states for each element correctly (+3 for Ac, +4 for Th, +5 for Pa, +6 for U and so on). This apart, the book offers a comprehensive introduction to the area.


38 09 | 2017


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