Nuclear chemistry naturally occurring radioactive

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. 

Chapter 16, Nuclear Chemistry, looks at the type of radioactive particles that are emitted from the nuclei of radioactive atoms. Equations are written and balanced for both naturally occurring radioactivity and artificially produced radioactivity. The half-lives of radioisotopes are discussed, and the amount of time for a sample to decay is calculated. Radioisotopes important in the field of nuclear medicine are described. Combining Ideas from Chapters 15 and 16 follows as an interchapter problem set. 

Some isotopes that occur in nature are unstable and are said to be radioactive. A few radioactive isotopes, such as uranium-238 and carbon-14, are found on Earth, and many others can be synthesized in nuclear chemistry laboratories, as we describe in Chapter 22. Over time, radioactive isotopes decompose into other stable isotopes. Unstable isotopes decompose in several ways. Most nuclei that have Z > 83 decompose by giving off a helium... 

Nuclear chemistry (radiochemistry) has now become a large and very important branch of science. Over four hundred radioactive isotopes have been made in the laboratory, whereas only about three hundred stable isotopes have been detected in nature. Three elements —technetium (43), astatine (85), and promethium (61), as well as some trans-uranium elements, seem not to occur in nature, and are available only as products of artificial transmutation. The use of radioactive isotopes as tracers has become a valuable technique in scientific and medical research. The controlled release of nuclear energy promises to lead us into a new world, in which the achievement of man is no longer limited by the supply of energy available to him. 

With the development of nuclear reactors and charged particle accelerators (commonly referred to as atom smashers ) over the second half of the twentieth century, the transmutation of one element into another has become commonplace. In fact some two dozen synthetic elements with atomic numbers higher than naturally occurring uranium have been produced by nuclear transmutation reactions. Thus, in principle, it is possible to achieve the alchemist s dream of transmuting lead into gold, but the cost of production via nuclear transmutation reactions would far exceed the value of the gold. SEE ALSO Alchemy Nuclear Chemistry Nuclear Fission Radioactivity Transactinides. 

Another branch of physical chemistry is nuclear chemistry. Nuclear chemists work with radioactive materials, which may occur naturally or be produced artificially in nuclear reactors. Nuclear chemists study the properties of these substances and investigate ways in which radioactive materials may be useful in a wide range of appUcations, including medicine and agriculture among other fields. 

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