plutonium

[ ploo-toh-nee-uh m ]

/ pluˈtoʊ ni əm /

noun Chemistry, Physics.

a transuranic element with a fissile isotope of mass number 239 (plutonium 239) that can be produced from non-fissile uranium 238, as in a breeder reactor. Symbol: Pu; atomic number: 94.

Nearby words

plutomania, pluton, plutonian, plutonic, plutonism, plutonium, plutus, pluvial, pluviometer, pluviosity, pluvious

Origin of plutonium

1940–45; < Greek Ploútōn Pluto + -ium

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for plutonium

When my oldest child was a toddler, I treated illuminated screens like plutonium.
Yes, Your Toddler Can Watch TV: The New Rules for Screen Time|Russell Saunders|December 26, 2014|DAILY BEAST
The plutonium was sent to a place called the Plutonium Finishing Plant.
At the Hanford Nuclear Reservation, a Steady Drip of Toxic Trouble|Eric Nusbaum|February 24, 2013|DAILY BEAST
So was the plutonium that went into the construction of the nuclear bomb Fat Man, which was detonated over Nagasaki.
At the Hanford Nuclear Reservation, a Steady Drip of Toxic Trouble|Eric Nusbaum|February 24, 2013|DAILY BEAST
Possibly as triumphant as ending World War II with a bomb made from plutonium developed here.
At the Hanford Nuclear Reservation, a Steady Drip of Toxic Trouble|Eric Nusbaum|February 24, 2013|DAILY BEAST

I drank an International Proton Pale Ale and opted not to follow it up with a Plutonium Porter.
At the Hanford Nuclear Reservation, a Steady Drip of Toxic Trouble|Eric Nusbaum|February 24, 2013|DAILY BEAST
Los Alamos scientists devised two designs for an atomic bomb--one using the uranium and another using the plutonium.
Trinity [Atomic test] Site|White Sands Missile Range Public Affairs Office
The core of the bomb consisted of two hemispheres of plutonium, (Pu-239), and an initiator.
Trinity [Atomic Test] Site|The National Atomic Museum
Rip added it to the front of the plutonium wedge, along with a piece of beryllium from the bomb, and Kemp welded it in place.
Rip Foster in Ride the Gray Planet|Harold Leland Goodwin
This resulted in the formation of 200 micrograms of plutonium.
A Brief History of Element Discovery, Synthesis, and Analysis|Glen W. Watson
After letting the temperatures of the plutonium and casing equalize the core slid smoothly into place.
Trinity [Atomic test] Site|White Sands Missile Range Public Affairs Office

British Dictionary definitions for plutonium

plutonium

/ (pluːˈtəʊnɪəm) /

noun

a highly toxic metallic transuranic element. It occurs in trace amounts in uranium ores and is produced in a nuclear reactor by neutron bombardment of uranium-238. The most stable and important isotope, plutonium-239, readily undergoes fission and is used as a reactor fuel in nuclear power stations and in nuclear weapons. Symbol: Pu; atomic no: 94; half-life of 239 Pu: 24 360 years; valency: 3, 4, 5, or 6; relative density (alpha modification): 19.84; melting pt: 640°C; boiling pt: 3230°C

Word Origin for plutonium

C20: named after the dwarf planet Pluto because Pluto lies beyond Neptune and plutonium was discovered soon after neptunium

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for plutonium

plutonium

transuranic element, 1942, from Pluto, the planet, + element ending -ium. Discovered at University of California, Berkeley, in 1941, the element named on suggestion of Seaborg and Wahl because it follows neptunium in the periodic table as Pluto follows Neptune in the Solar System. The name plutonium earlier had been proposed for barium and was sometimes used in this sense early 19c.

Medicine definitions for plutonium

plutonium

[ plōō-tō′nē-əm ]

n. Symbol Pu

A naturally radioactive, metallic transuranic element, occurring in uranium ores or produced artificially by neutron bombardment of uranium, used in radionuclide batteries in pacemakers. Its longest-lived isotope is Pu 244 with a half-life of 77 million years. Atomic number 94.

Science definitions for plutonium

plutonium

[ plōō-tō′nē-əm ]

Pu

A silvery, radioactive metallic element of the actinide series that has the highest atomic number of all naturally occurring elements. It is found in minute amounts in uranium ores and is produced artificially by bombarding uranium with neutrons. It is absorbed by bone marrow and is highly poisonous. Plutonium is used in nuclear weapons and as a fuel in nuclear reactors. Its longest-lived isotope is Pu 244 with a half-life of 80 million years. Atomic number 94; melting point 640°C; boiling point 3,228°C; specific gravity 19.84; valence 3, 4, 5, 6. See Periodic Table.

Culture definitions for plutonium

plutonium

[ (plooh-toh-nee-uhm) ]

A radioactive chemical element that is artificially derived from uranium.

Note

Plutonium is used in nuclear reactors.