pan> 5s 2
5p 6
5d 10
5f 12
6s 2
6p 6
7s 2
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History:
Fermium-525 was discovered in 1952 in the debris field of a hydrogen bomb explosion in the Pacific Ocean. It was discovered by Ghiorso and co-workers and is the eight discovered transuranium element of the actinide series. The longest lived fermium isotope lived a half life of 82 days. p> Discovered by: Workers at Argonne, Los Alamos, USA, and the University of California at Berkeley, USA. p> Discovered at: USA
Discovered when: 1 952
Fermium (after Enrico Fermi) was first discovered by a team led by Albert Ghiorso in 1952. The team found 255 Fm in the debris of the first hydrogen bomb explosion. That isotope was created when 238 U 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 whose team members included Ghiorso, Stanley G. Thompson, Gary H. Higgins, Glenn T. Seaborg, Martin H. Studier, P.R. Fields, Sherman M. Fried, H. Diamond, J.F. Mech, and so on. Samples of sea coral impacted from the first thermonuclear explosion of November 1952 were used. All these findings were kept secret until 1955 due to Cold War tensions. In late 1953 and early 1954 a team from the Nobel Institute of Physics in Stockholm bombarded a 238 U target with 16 O ions, producing an alpha-emitter with an atomic weight of ~ 250 and with 100 protons (in other words, element 250 100). The Nobel team did not claim discovery but the isotope they produced was later positively identified as 250 Fm.
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Binary Compounds
This section lists some binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and some other compounds of fermium. For each compound, a formal oxidation number for fermium is given, but the usefulness of this number is limited for p -block elements in particular. Based upon that oxidation number, an electronic configuration is also given but note that for more exotic compounds you should view this as a guide only. The term hydride is used in a generic sense to indicate compounds of the type M x H y . In compounds of fermium (where known), the most common oxidation numbers of fermium are: 3 . Chlorides - FmCl 2 : fermium (II) chloride
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Basic Facts:
There are eighteen known isotopes and all of them are radio active. Fermium is made by subjecting elements like uranium and plotomium to intense nuetron bombardment. <В
Isotope:
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17 radioisotopes of fermium have been characterized, with the most stable being 257 Fm with a half-life of 100.5 days, 253 Fm with a half-life of 3 days, 252 Fm with a half-life of 25.39 hours, and 255 Fm 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, 250m Fm (T ВЅ 1.8 seconds). The isotopes of fermium range in atomic weight from 242.073 amu ( 242 Fm) to 259.101 amu ( 259 Fm).
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Notable characteristics:
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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. Fm and heavier [[isotope]] s can be synthesized by intense neutron bombardment of lighter elements especially uranium and plutonium.
В«З ферми в вашої крові ви будете жити довго! В»
Глава 1. Біографія
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Фізика в Римі
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