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10 Plutonium Facts

Facts about the element Plutonium


Pure plutonium is silvery, but acquires a yellowish tarnish as it oxidizes.

Pure plutonium is silvery, but acquires a yellowish tarnish as it oxidizes. Photo is of gloved hands holding a button of plutonium.

Deglr6328, wikipedia.org
You probably know plutonium is an element and that plutonium is radioactive, but what other facts do you know? Here are 10 useful and interesting facts about plutonium. You can get more detailed information about plutonium visiting its element fact sheet.
  1. The element symbol for plutonium is Pu, rather than Pl, because this was a more amusing, easily-remembered symbol.

  2. Pure plutonium is a silvery-white metal, although it quickly oxidizes in air to a dull finish.

  3. The atomic number of plutonium is 94, meaning all atoms of plutonium have 94 protons.

  4. Plutonium oxide forms on the surface of plutonium exposed to air. The oxide is pyrophoric, so pieces of plutonium may glow like embers as the outer coating burns.

  5. Ordinarily, there are six allotropes or forms of plutonium. A seventh allotrope exists at high temperatures.

  6. Plutonium displays colorful oxidation states in aqueous solution. These states tend not to be stable, so plutonium solutions may spontaneously change oxidation states and colors.

  7. Unlike most substances, plutonium increases in density as it melts. The increase in density of about 2.5%. Near its melting point, liquid plutonium also exhibits higher-than-usual viscosity and surface tension for a metal.

  8. Plutonium is used in radioisotope thermoelectric generators, which are used to power spacecraft. The element has been used in nuclear weapons, including the Trinity test and bomb that was dropped on Nagasaki. Plutonium-238 is used to power some heart pacemakers.

  9. Plutonium and its compounds are toxic and accumulate in bone marrow. Inhalation of plutonium and its compounds increases the risk of lung cancer, although there are many people who have inhaled substantial amounts of plutonium yet did not develop lung cancer. Inhaled plutonium is said to have a metallic taste.

  10. Criticality accidents involving plutonium have occurred. The amount of plutonium required for critical mass is about one-third that necessary for uranium-235. Plutonium in solution is more likely to form critical mass than solid plutonium because the hydrogen in water acts as a moderator.

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