plutonium
- Domaine
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- chimiechimie minérale
- Date
Définition :
Corps simple de symbole Pu, de numéro atomique 94; préparé sous forme d'éléments isotopiques 238 et 239. Ce dernier est le plus important, à cause de sa fission par les neutrons lents. Corps blanc d'argent, pyrophorique; attaque lentement l'eau; s'unit aux halogènes, à l'acide sulfurique, aux acides chlorhydrique, perchlorique à 72 % trichloracétique.
Termes :
- plutonium n. m.
- Pu
Traductions
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anglais
Date :Définition
An element. State: solid; group: IIIB (actinide); atomic no.: 94; atomic wt.: 239.11; valence: 3,4,5,6. A highly radioactive and fissionable element of the transuranium series, m.p. 641 °C (1186 °F), first produced in observable amounts in 1941 by bombardment of uranium with deuterons in a cyclotron. It exists in six allotropic crystalline forms. It is a much more efficient fissioning agent than uranium-235, which it has largely replaced as a nuclear reactor fuel. It is now made in a reactor from natural uranium by neutron bombardment of the 238 isotope to form U-239, which is thus converted into plutonium.
Note :
Its commercial use is chiefly in electric power reactors; it is extremely dangerous to handle, and operations must be done by remote control and with adequate shielding.
Termes :
- plutonium
- Pu
[Pu] Symbol for the element plutonium, named after the outermost planet Pluto, by analogy with its location in the Solar System. At the time of its discovery, plutonium was thought to be the last of the transuranic elements.