Transfermium elements

The lUPAC Commission on Nomenclature of Inorganic Chemistry continues its work, which is effectively open-ended. Guidance in the use of lUPAC rules (38) as well as explanations of their formulation (39) are available. A second volume on nomenclature of inorganic chemistry is in preparation it will be devoted to specialized areas. Some of the contents have had preliminary pubHcation in the journal Pure andJipplied Chemist, eg, "Names and Symbols of Transfermium Elements" in 1944. 

Transfermium elements, names of, 17 387t Transfer molding, 10 458 of Teflon PFA, 18 337 of thermosetting resins, 19 557-558 Transfer of copyrights, 7 788-791 Transfer panels, 11 33-34 Transfer printing, 9 221, 242 Transfer processes, relationship among, 15 731... 

The synthesis of transfermium elements beyond Fm is succeeded by nuclear reactions of charged particles with targets of an actinide element of a lower atomic number. 

Glenn Seaborg later went on to find a number of other elements. One of those elements, atomic number 106, was named seaborgium in his honor. (See transfermium elements entty in this volume.)... 

The term transfermium describes the elements with atomic numbers greater than 100. Fennium is element 100, so transktmium means beyond fermium. The transfermium elements are grouped together for a number of reasons. First, they are all prepared artificially. None of them has been found to occur in Earth s crust naturally. Second, they can be made with only the greatest difficulty. In fact, no more than a few atoms of some transfermium elements have been created so far. Third, very little is known about the transfermium elements. With only a few atoms to study, it is difficult to learn much about them. 

Still, the transfermium elements are of great interest to chemists and physicists. They help answer questions about the periodic table. The periodic table is a chart that shows how chemical elements are related to each other. The transfermium elements are found at the very end of the periodic table. Scientists want to know if there is a limit to how heavy a chemical element can be. They also want to know what the properties of these very heavy elements will be like. 

The following chart provides basic information about the transfermium elements that have been officially recognized and named. 

Transfermium element Any element with an atomic number greater than 100. 

A discussion of the names and symbols in the transfermium elements chart follows in the next section. 

All transfermium elements are made in particle accelerators, or atom smashers. A particle accelerator is a machine that makes particles move very fast. These particles may be as small as protons or positrons or as large as ions of atoms such as nickel and zinc. They often go nearly as fast as the speed of light. Light travels about 186,000 miles per second (300,000 kilometers per second). 

Credit for discovery of a transfermium element is extremely complicated. In most cases, no more than a handful of atoms is produced in an atom smasher. For example, the Dubna group first claimed to have found element 104 in 1964, but many scientists doubted this report. Five years later, American scientists also reported making element 104. This time, the evidence was better. 

In April 2008, a research group from the Hebrew University in Jerusalem, under the direction of Amnon Marinov, reported the discovery of a few individual atoms of unbibium in natural thorium reserves. That report has been strongly criticized and no supporting evidence has been produced yet. If true, the results would be astounding. It would be the first time that a transfermium element had been found as a natural product. 

No one knows much about the properties of the transfermium elements. It isn t possible to see or touch or smell or taste any of these elements. There are often no more than a few dozen atoms to study. 

Most transfermium elements have more than one isotope. Isotopes are two or more forms of an element. Isotopes differ from each other according to their mass number. The number written to the right of the element s name is the mass number. The mass number represents the number of protons plus neutrons in the nucleus of an atom of the element. The number of protons determines the element, but the number of neutrons in the atom of any one element can vary. Each variation is an isotope. 

All of the isotopes of the transfermium elements are radioactive. A radioactive isotope is one that breaks apart and gives off some form of radiation. 

Elements with atomic numbers 1 through 100 are presented in separate entries. The transfermium elements (elements 101 through 112) are covered in one entry, which also discusses six additional elements (113, 114, 115, 116, 118, and 122) that have yet to be confirmed by the International Union of Pure and Applied Chemistry (lUPAC). 

D. H. Wilkinson, Discovery of the Transfermium Elements, Prog. Particle Nucl. Phys. 29, 453-530 (1992). Also published, with comments in Pure Appl. Chem. 63, 879-86 (1991) and 65, 1757-814, 1815-24 (1993). 

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