What does plutonium mean?
Plutonium is a radioactive chemical element in the actinide series, identified by the symbol Pu and atomic number 94. Although tiny amounts occur naturally, most plutonium is manufactured when neutrons strike uranium in nuclear reactors. Different isotopes have different uses: some plutonium isotopes can serve as fuel for nuclear power, while plutonium-239 can be used in nuclear weapons. The word is therefore closely associated with nuclear energy, weapons, and the secure handling of nuclear materials. In ordinary discussion, “plutonium” often means the strategically sensitive material produced in reactors, rather than the chemical element in a purely scientific context. The name was deliberately chosen to reflect its position near uranium and neptunium in the periodic table and to honor the world Pluto.
nounA radioactive metallic chemical element of the actinide series, with the symbol Pu and atomic number 94. Plutonium is produced in nuclear reactors, and some isotopes are used as nuclear fuel or in weapons.
- A radioactive chemical element of the actinide series, especially when referring to the material produced in nuclear reactors or used in nuclear weapons.
"The reactor produces plutonium that can be separated and used to make additional nuclear fuel."
"The laboratory analyzed samples of plutonium to determine their isotopic composition."
"International inspectors verified that the facility had declared and secured its plutonium stockpile."
Usually uncountable; no regular plural is used.
"The inspectors confirmed that the plutonium was stored in secured containers."
Plutonium is element 94, named after the distant world Pluto, and it is one of the materials at the heart of nuclear power and nuclear weapons.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does plutonium come from?
The name plutonium was created in the 1940s by American scientists who discovered the element during their study of transuranium elements. It was formed from Pluto, the name of the dwarf planet, plus the chemical suffix -ium, in keeping with the names of related elements. Related words such as plutonian and plutonic also derive from Pluto.
How plutonium is actually used
In general use, the word usually refers to a quantity or material associated with nuclear technology and may carry strong connotations of radioactivity, weapons, or geopolitical sensitivity. The element symbol is Pu.
Easily confused with plutonium
Both are radioactive chemical elements, but polonium is atomic number 84 and is named after Poland, whereas plutonium is atomic number 94 and is named after Pluto.