plutonium

[ploo-toh-nee-uhm]

noun

Chemistry, Physics.

1. 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. Pu; 94.

plutonium

/ pluːˈtəʊnɪəm /

noun

1. 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

plutonium

1. 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.

2. See Periodic Table

plutonium

1. A radioactive chemical element that is artificially derived from uranium.

Plutonium is used in nuclear reactors.

Word History and Origins

Origin of plutonium¹

1940–45; < Greek Ploútōn Pluto + -ium

Word History and Origins

Origin of plutonium¹

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

Example Sentences

The site opened in the 1950s, when it was creating plutonium to be used in the core of nuclear bombs.

From BBC

Spent fuel from heavy water reactors contains plutonium suitable for a nuclear bomb.

From BBC

Heavy-water reactors produce plutonium, which - like enriched uranium - can be used to make the core of an atom bomb.

From BBC

The government says it will dispose of its 140 tonnes of radioactive plutonium - currently stored at a secure facility at Sellafield in Cumbria.

From BBC

In 1974, India shocked the world by detonating a nuclear device, drawing outrage from Canada, which accused India of extracting plutonium from a Canadian reactor, a gift intended solely for peaceful use.

From BBC