AskDefine | Define fermium

Dictionary Definition

fermium n : a radioactive transuranic metallic element produced by bombarding plutonium with neutrons [syn: Fm, atomic number 100]

User Contributed Dictionary

see Fermium



Named for Enrico Fermi


  1. a transuranic chemical element (symbol Fm) with an atomic number of 100.

Related terms


External links

For etymology and more information refer to: (A lot of the translations were taken from that site with permission from the author)



  1. fermium



  1. fermium

Extensive Definition

Fermium () is a synthetic element with the symbol Fm and atomic number 100. A highly radioactive metallic transuranic element of the actinide series, fermium is made by bombarding plutonium with neutrons and is named after nuclear physicist Enrico Fermi. Fermium is the eighth transuranic element.

Notable characteristics

Only small amounts of fermium have ever been produced or isolated. Thus relatively little is known about its chemical properties. Only the (III) oxidation state of the element appears to exist in aqueous solution. 254Fm and heavier isotopes can be synthesized by intense neutron bombardment of lighter elements (especially uranium and plutonium). During this, successive neutron captures mixed with beta decays build the fermium isotope. The intense neutron bombardment conditions needed to create fermium exist in thermonuclear explosions and can be replicated in the laboratory (such as in the High Flux Isotope Reactor at Oak Ridge National Laboratory). The synthesis of element 102 (nobelium) was confirmed when 250Fm was chemically identified.


There are no known uses of fermium outside of basic research.


Fermium (after Enrico Fermi) was first discovered by a team led by Albert Ghiorso in 1952. The team found 255Fm in the debris of the first hydrogen bomb explosion (see Operation Ivy). That isotope was created when 238U combined with 17 neutrons in the intense temperature and pressure of the explosion (eight beta decays also occurred to create the element). The work was overseen by the University of California Radiation Laboratory, Argonne National Laboratory, and Los Alamos Scientific Laboratory. All these findings were kept secret until 1955 due to Cold War tensions. Samples of sea coral impacted from the first thermonuclear explosion of November 1952 were used.
In late 1953 and early 1954 a team from the Nobel Institute of Physics in Stockholm bombarded a 238U target with 16O ions, producing an alpha-emitter with an atomic weight of ~250 and with 100 protons (in other words, element 250100). The Nobel team did not claim discovery until 1954. The isotope they produced was later positively identified as 250Fm.


17 radioisotopes of fermium have been characterized, with the most stable being 257Fm with a half-life of 100.5 days, 253Fm with a half-life of 3 days, 252Fm with a half-life of 25.39 hours, and 255Fm with a half-life of 20.07 hours. All of the remaining radioactive isotopes have half-lives that are less than 5.4 hours, and the majority of these have half-lives that are less than 3 minutes. This element also has 1 meta state, 250mFm (t½ 1.8 seconds). The isotopes of fermium range in atomic weight from 242.073 u (242Fm) to 259.101 u (259Fm).


External links

fermium in Arabic: فرميوم
fermium in Azerbaijani: Fermium
fermium in Bengali: ফার্মিয়াম
fermium in Belarusian: Фермій
fermium in Bosnian: Fermijum
fermium in Catalan: Fermi (element)
fermium in Czech: Fermium
fermium in Corsican: Fermiu
fermium in Danish: Fermium
fermium in German: Fermium
fermium in Estonian: Fermium
fermium in Modern Greek (1453-): Φέρμιο
fermium in Spanish: Fermio
fermium in Esperanto: Fermio
fermium in Basque: Fermio
fermium in French: Fermium
fermium in Friulian: Fermi
fermium in Manx: Fermium
fermium in Galician: Fermio
fermium in Korean: 페르뮴
fermium in Armenian: Ֆերմիում
fermium in Croatian: Fermij
fermium in Italian: Fermio
fermium in Hebrew: פרמיום
fermium in Javanese: Fermium
fermium in Haitian: Fèmyòm
fermium in Latin: Fermium
fermium in Latvian: Fermijs
fermium in Luxembourgish: Fermium
fermium in Lithuanian: Fermis
fermium in Lojban: jinmrfermi
fermium in Hungarian: Fermium
fermium in Malayalam: ഫെര്‍മിയം
fermium in Marathi: फर्मियम
fermium in Dutch: Fermium
fermium in Japanese: フェルミウム
fermium in Norwegian: Fermium
fermium in Norwegian Nynorsk: Fermium
fermium in Polish: Ferm (pierwiastek)
fermium in Portuguese: Férmio
fermium in Russian: Фермий
fermium in Simple English: Fermium
fermium in Slovak: Fermium
fermium in Slovenian: Fermij
fermium in Serbian: Фермијум
fermium in Serbo-Croatian: Fermijum
fermium in Saterfriesisch: Fermium
fermium in Finnish: Fermium
fermium in Swedish: Fermium
fermium in Thai: เฟอร์เมียม
fermium in Turkish: Fermiyum
fermium in Ukrainian: Фермій
fermium in Chinese: 镄
Privacy Policy, About Us, Terms and Conditions, Contact Us
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2
Material from Wikipedia, Wiktionary, Dict
Valid HTML 4.01 Strict, Valid CSS Level 2.1