Radioactive lanthanide isotopes, separation

Neutron-rich lanthanide isotopes occur in the fission of uranium or plutonium and ate separated during the reprocessing of nuclear fuel wastes (see Nuclearreactors). Lanthanide isotopes can be produced by neutron bombardment, by radioactive decay of neighboring atoms, and by nuclear reactions in accelerators where the rate earths ate bombarded with charged particles. The rare-earth content of solid samples can be determined by neutron... 

Lanthanides and Radioactive Nuclides Complexes Isotopic Separation... 

During the first decade of the 20th century the application of physics to chemistry once and for all established the reahty of atoms. Physicists even weighed the electrons that are now known to govern chemical properties. The discovery of radioactive particles alpha [a] and beta [P]) led to the earliest perceptions of isotopes. The remaining two natural rare earths were finally separated and identified, completing the lanthanide series of chemical elements. 

The actinides and lanthanides make up the f-block of the periodic table. These two rows are frequently separated from the main table, but that s just so the periodic table isn t so wide on a piece of paper (seriously). Many of these elements have radioactive isotopes, but the rate at which they decay can vary immensely. For example, has a half-life of 4.5 billion years, but has a half-life of only seventy-two seconds ... 

Scandium, yttrium, and the lanthanides represent 17% of all of the elements that can be obtained in coherent form. In view of their similar chemical behavior separation of these elements proved to be formidable (Szabadvary, 1988) but all of the metals have now been obtained in relatively high purity and, except for promethium, their thermodynamic properties have been measured with varying degrees of quality. Based on the interpolation of the properties of neighboring elements, it has also been possible to estimate the thermodynamic properties of promethium in order to complete this review. Because of the radioactive nature of this element and the fact that the most stable isotope has half-life of only 17.7 years, it is unlikely that further measurements will be carried out beyond the very basic properties which have already been determined. 

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