n. Symbol Pu
A radioactive, silvery, metallic transuranic element, occurring in uranium ores and produced artificially by neutron bombardment of uranium. Its longest-lived isotope is Pu-244 with a half-life of 80 million years. It is a radiological poison, specifically absorbed by bone marrow, and is used, especially the highly fissionable isotope Pu-239, as a reactor fuel and in nuclear weapons. Atomic number 94; melting point 640°C; boiling point 3,228°C; specific gravity 19.84 (25°C); valence 3, 4, 5, 6. See Periodic Table.
[After the dwarf planet PLUTO (from the fact that it follows neptunium in the periodic table).]
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Indo-European & Semitic Roots Appendices
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