Transactinide element


Transactinide element

In chemistry, transactinide elements are the chemical elements with atomic numbers greater than those of the actinides, the heaviest of which is lawrencium (103). [ [http://www.iupac.org/reports/provisional/abstract04/connelly_310804.html IUPAC Provisional Recommendations for the Nomenclature of Inorganic Chemistry (2004)] (online draft of an updated version of the "Red Book" IR 3-6)] The transactinide elements are also called super-heavy elements.

All transactinide elements are also transuranium elements, that is, have an atomic number greater than that of uranium (92), an actinide. The further distinction of having a greater atomic number than the actinides is significant in several ways:

*The transactinide elements all have electrons in the 6d subshell in their ground state (and thus are placed in the d-block). The last actinide, lawrencium, also has one electron in the 6d subshell.
*Except for dubnium, even the longest-lasting isotopes of transactinide elements have extremely short half-lives, measured in seconds, or smaller units.
*The element naming controversy involved the first five or six transactinide elements. These elements thus used three-letter systematic names for many years after their discovery had been confirmed. (Usually the three-letter names are replaced with two-letter names relatively shortly after a discovery has been confirmed.)

All of the transactinide elements are radioactive and have only been obtained synthetically in laboratories. None of these elements has ever been collected in a macroscopic sample. Transactinide elements are all named after nuclear physicists and chemists or important locations involved in the synthesis of the elements.

Chemistry Nobelist Glenn T. Seaborg who first proposed the actinide concept which led to the acceptance of the actinide series also proposed the existence of a transactinide series ranging from element 104 to 121 and a superactinide series approximately spanning elements 122 to 153. One of the transactinide elements, Seaborgium, was named in his honor.

The term transactinide is an adjective, and is not commonly used alone as a noun to refer to the transactinide elements.

List of the transactinide elements:

*104 Rutherfordium, Rf
*105 Dubnium, Db
*106 Seaborgium, Sg
*107 Bohrium, Bh
*108 Hassium, Hs
*109 Meitnerium, Mt
*110 Darmstadtium, Ds
*111 Roentgenium, Rg
*112 Ununbium, Uub*
*113 Ununtrium, Uut*
*114 Ununquadium, Uuq*
*115 Ununpentium, Uup*
*116 Ununhexium, Uuh*
*118 Ununoctium, Uuo*

* The synthesis of these elements has not been officially attested by IUPAC, while in several cases previous syntheses have been confirmed by other institutions or other methods. The names and symbols given are provisional as no names for the elements have been agreed on.

See also

* Transuranium element
* Bose-Einstein condensate (also known as "Superatom")
* Island of stability

References


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Look at other dictionaries:

  • transactinide — [trans ak′tə nīd΄, tranzak′tə nīd΄] n. any of the radioactive chemical elements that have atomic numbers higher than the highest actinide (lawrencium): also called transactinide element transactinic [trans΄ak tin′ik] adj …   English World dictionary

  • transactinide — ● transactinide nom masculin Nom générique des éléments qui suivent les actinides dans la classification périodique. transactinide n. m. CHIM élément dont le numéro atomique est supérieur à ceux des actinides …   Encyclopédie Universelle

  • element 110 — n. a radioactive chemical element with a very short half life: a transactinide produced by bombarding any of various heavy elements, esp. lead, with high energy nuclear particles: at. no., 110; ununnilium: see the periodic table of elements in… …   Universalium

  • element 111 — n. a radioactive chemical element with a very short half life: a transactinide produced by bombarding bismuth with nickel atoms: at. no., 111; unununium: see the periodic table of elements in the Reference Supplement * * * element 111 n. An… …   Universalium

  • element 112 — n. a radioactive chemical element with a very short half life: a transactinide produced by bombarding lead with zinc ions: at. no., 112; ununbium: see the periodic table of elements in the Reference Supplement * * * element 112 n. An artificially …   Universalium

  • element 110 — n. a radioactive chemical element with a very short half life: a transactinide produced by bombarding any of various heavy elements, esp. lead, with high energy nuclear particles: at. no., 110; ununnilium: see the periodic table of elements in… …   English World dictionary

  • element 111 — n. a radioactive chemical element with a very short half life: a transactinide produced by bombarding bismuth with nickel atoms: at. no., 111; unununium: see the periodic table of elements in the Reference Supplement …   English World dictionary

  • element 112 — n. a radioactive chemical element with a very short half life: a transactinide produced by bombarding lead with zinc ions: at. no., 112; ununbium: see the periodic table of elements in the Reference Supplement …   English World dictionary

  • Transactinide — On qualifie de transactinide tout élément chimique dont le numéro atomique est supérieur à celui du lawrencium (n° 103), le dernier des actinides[1]. Les transactinides sont également appelés éléments superlourds. Ce sont, par définition,… …   Wikipédia en Français

  • Élément 118 — Ununoctium Ununoctium Ununs …   Wikipédia en Français


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