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Plutonium longest lived isotope

The discovery of Pu has been described in detail by Seaborg in his Plutonium Story (chapter 1 of the book The Transuranium Elements 1958). First, the separation of Pu from Th caused some difficulties, because both elements were in the oxidation state 4-4. After oxidation of Pu(IV) by persulfate to Pu(VI), separation became possible. Pu is produced in appreciable amounts in nuclear reactors (section 14.1), but it has not immediately been detected, due to its low specific activity caused by its long half-life. After the discovery of Pu, plutonium gained great practical importance, because of the high fission cross section of Pu by thermal neutrons. Very small amounts of Pu are present in uranium ores, due to (n, y) reaction of neutrons from cosmic radiation with The ratio Pu/ U is of the order of 10 In 1971, the longest-lived isotope of plutonium, Pu (ri/2 = 8.00 lO y) was found by Hoffman in the Ce-rich rare-earth mineral bastnaesite, in concentrations of the order of 10 gAg-... [Pg.285]

On the earth, the most likely source of macroscopic amounts for technetium and promethium is the reprocessing of irradiated uranium and plutonium from fission reactors. This mechanism produces only a few, and not the longest-lived, isotopes. [Pg.697]

The longest-lived isotope of americium is Am with a half-life of about 7370 years. Other relatively long-lived isotopes are Am and Am. Americium can also form four oxidation states in aqueous solution trivalent, tetravalent, pentavalent and hexavalent. No data are available for the tetravalent and hex-avalent oxidation states and only a relatively small amount for both the trivalent and pentavalent states. The behaviour of all oxidation states should be reasonably similar to those of uranium, neptunium and plutonium. [Pg.407]

Pu. The isotope Pu is the longest-lived of the plutonium- isotopes, with a half-life of 8 X 10 years. It can be produced by neutron absorption in Pu, but because of the short half-life and low concentration of Pu only minute quantities of Pu, of the order of 10" percent, are present in reactor-produced plutonium [K2]. Small quantities of Pu, as well as Pu and Pu, are present in the residues from nuclear explosions, resulting from the decay of the neutron-rich uranium isotopes and formed by multiple neutron capture in the high neutron... [Pg.428]

Laboratory. The isotope produced was the 20-hour Fm. During 1953 and early 1954, while discovery of elements 99 and 100 was withheld from publication for security reasons, a group from the Nobel Institute of Physics in Stockholm bombarded with O ions, and isolated a 30-min a-emitter, which they ascribed to 100, without claiming discovery of the element. This isotope has since been identified positively, and the 30-min half-life confirmed. The chemical properties of fermium have been studied solely with tracer amounts, and in normal aqueous media only the (III) oxidation state appears to exist. The isotope and heavier isotopes can be produced by intense neutron irradiation of lower elements such as plutonium by a process of successive neutron capture interspersed with beta decays until these mass numbers and atomic numbers are reached. Twenty isotopes and isomers of fermium are known to exist. Fm, with a half-life of about 100.5 days, is the longest lived. °Fm, with a half-life of 30 min, has been shown to be a product of decay of Element 102. It was by chemical identification of Fm that production of Element 102 (nobelium) was confirmed. Fermium would probably have chemical properties resembling erbium. [Pg.643]


See other pages where Plutonium longest lived isotope is mentioned: [Pg.186]    [Pg.553]    [Pg.158]    [Pg.236]    [Pg.24]    [Pg.882]    [Pg.428]    [Pg.71]    [Pg.43]    [Pg.663]    [Pg.655]    [Pg.497]    [Pg.708]    [Pg.239]    [Pg.737]    [Pg.714]    [Pg.701]    [Pg.735]    [Pg.655]   
See also in sourсe #XX -- [ Pg.755 ]




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