Plutonium

**Definition:** A naturally radioactive element of the actinide metals series. It has the atomic symbol Pu, and atomic number 94. 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.

**Tree numbers:** - D01.268.271.100.700 - D01.268.556.700 - D01.496.749.305.100.700 - D01.552.020.734 - D01.552.544.700