plutonium

n. radioactive chemical element

This article is about the radioactive element. For other meanings, see Plutonium (disambiguation). Plutonium (IPA: ) is a radioactive, metallic chemical element. It has the symbol Pu and the atomic number 94. It is the element used in most modern nuclear weapons. The most significant isotope of plutonium is 239Pu, with a half-life of 24,100 years. It can be made from natural uranium and is fissile. The most stable isotope is 244Pu, with a half-life of about 80 million years, long enough to be found in extremely small quantities in nature. In fact, 244Pu is the nucleon-richest atom that naturally occurs in the Earth's crust, albeit in small traces.
See more at Wikipedia.org...

Noun
1. a solid silvery gray 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
(synonym) Pu, atomic number 94
(hypernym) chemical element, element
(hyponym) plutonium 239

n. plutonium, Pu, radioactive element (Chemistry)

n. plutonium, radioactive chemical element