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- Name : Plutonium
- Symbol : Pu
- Atomic # : 94
- Atom weight: 242 (Most stable isotope)
- Melting P. : 641
- Boiling P. : 3232
- Oxidation : +3, +4, +5, +6
- Pronounced : ploo-TOE-ni-em
- From : Named for the planet Pluto
- Identified : Glenn T. Seaborg in 1941
- Appearance : Silvery-white, radioactive metal
- Note : Byproducts of atomic power plants
- Main ingredient in atomic fission weapons
-
- [Properties]
-
- All isotopes of plutonium are radioactive. The half-lives range from about
- 26 minutes for plutonium-235 to 82-million years for plutonium-244. The most
- widely produced isotopes, however are plutonium-238 and -239.
- There are six known allotropic, crystalline, metallic forms of plutonium.
- The alpha version is the one that exists at normal environmental
- temperatures, so it is most widely recognized. The remaining allotropic form
- exist at higher temperatures. A sample of alpha plutonium has a silvery
- color that takes on a yellowish hue as it oxidizes in the air.
- A softball-sized piece of plutonium would grow hot to the touch because of
- its high level of alpha reaction. A somewhat larger sample can boil a litre
- of water within a few minutes. A single kilogram of Pu-238 can release the
- equivalent of 22-million kilowatt-hours of heat energy.
- Plutonium-238 is not fissionable; it cannot undergo a chain reaction.
- Plutonium-239, on the other hand, is fissionable and can undergo a chain
- reaction when compressed to its critical mass. In fact, the critical mass of
- plutonium-239 is only about one-third that of fissionable uranium-235. A
- kilogram of Pu-239 can release the explosive energy of 20,000 tons of TNT,
- making it the material of choice for fission weaponry.
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