1. A solid silvery grey radioactive transuranic element whose atoms can be split when bombarded with neutrons; found in minute quantities in uranium ores but is usually synthesized in nuclear reactors; 13 isotopes are known with the most important being plutonium 239
   "weapons-grade plutonium";
   - Pu, atomic number 94

Derived forms: plutoniums

Type of: chemical element, element

Encyclopedia: Plutonium