College of Arts and Sciences

Nuclear Chemistry and Radiochemistry

The course begins with an advanced treatment of nuclear structure, nuclear reactions, and radioactive decay processes. Introductions to topics in the closely allied fields of nuclear chemistry and radiochemistry will include the interaction of radiation with matter, radiation detection and measurement, nuclear activation analysis, isotope effects, radiation chemistry, hot-atom chemistry, nuclear age-dating methods, radiochemical separations, nuclear reactors, and nuclear power.

Isotopes are atoms of the same element that vary in the number of neutrons they contain. Radiochemistry is the chemical study of radioactive elements, both natural and artificial, and their use in the study of chemical processes. This includes the study of (i) the behavior of radioactive isotopes (radionuclides) (ii) chemical effects of high-energy radiation (iii) nuclear analytical methods (iv) the application of radionuclides in areas outside of chemistry such as medicine (v) the physics and chemistry of the radionuclides and (vi) radiotracer techniques.

For example, the heaviest known element has a nucleus with 118 protons. It finalizes the seventh period of the periodic table of elements. Element 118 was first created by a team of Russian and American scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia in 2002. By bombarding a target that included the isotope californium-249 with an intense beam of calcium-48, these scientists created just three atoms containing 176 neutrons, labeled ununoctium-294 (118 protons + 176 neutrons = ununoctium-294). The High Flux Isotope Reactor and Radiochemical Engineering Development Center at Oak Ridge National Laboratory prepared the actinide targets and shipped them to Dubna for experiments producing the latest six elements (Z = 113-118). In 2016, ununoctium was officially named oganesson after the team leader Yuri Oganessian. Tennessine (Ts) was the most recently discovered element (Z = 117), produced by bombardment of a berkelium-249 target with a calcium-48 beam, and named for the significant efforts of ORNL, UT Knoxville and Vanderbilt scientists and engineers in the JINR collaboration.

Because heavy nuclei contain so many particles, the atoms are unstable and split into smaller, so-called daughter products. As the atom breaks apart, energy is released in the form of electromagnetic waves and electrically charged particles. This energy is known as radiation. Data from the production of heavy transactinide elements (Z = 104-118) have indicated a considerable increase in the stability of the heaviest nuclei, confirming predictions and theoretical models suggesting the existence of what is known as the “island of stability”, first proposed by Glenn T. Seaborg in the 1960’s. Additionally, the most stable nuclides in this series have provided an opportunity to explore the chemistry of the elements, which in some cases have demonstrated significant departures from periodic trends.