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Fermium longest lived isotope

Such methods have allowed all the elements of the 6d series, i.e. to Z = 112, to be produced. However, these heavy elements are not available in sufficient quantities for conventional chemical studies and so will not be considered further here. Beyond fermium, even the longest-lived isotopes of the elements are highly radioactive, having only short half-lives (e.g. 53 d for Md, 185 s for No and 45 s for Lr). [Pg.5]

The original einsteinium isotope discovered in Enewetak fallout was Es with a half-life of 20 days. Eventually other einsteinium isotopes were created under controlled conditions. The longest-lived is Es, ty, = 275 days. The longest-lived isotope of fermium is Fm, ti/, = 100.5 days. Chemically speaking, einsteinium and fermium are... [Pg.179]

Sixteen isotopes of fermium are known to exist. 257Fm, with a half-life of about 100.5 days, is the longest lived. 250Fm, with a half-life of 30 minutes, has been shown to be a decay product of element 254-102. Chemical identification of 250Fm confirmed the production of element 102 (nobelium). [Pg.212]

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]

ISOTOPES There are a total of 21 isotopes of fermium. Their half-lives range from fer-mium-258 s 370 microseconds to fermium-257 s 100.5 days, which is the longest of all its isotopes. None of fermium s isotopes exist in nature. All are artificially produced and are radioactive. [Pg.330]


See other pages where Fermium longest lived isotope is mentioned: [Pg.186]    [Pg.158]    [Pg.306]    [Pg.663]    [Pg.655]    [Pg.708]    [Pg.881]    [Pg.737]    [Pg.714]    [Pg.755]    [Pg.701]    [Pg.735]    [Pg.655]   
See also in sourсe #XX -- [ Pg.755 ]




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