| plutonium | <chemical> Plutonium. A naturally radioactive element of the actinide metals series. It has the atomic symbol pu, atomic number 94, and atomic weight 242. Plutonium is used as a nuclear fuel, to produce radioisotopes for research, in radionuclide batteries for pacemakers, and as the agent of fission in nuclear weapons. Chemical name: Plutonium (12 Dec 1998) |
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