Isotopes of tungsten


Isotopes of tungsten

Naturally occurring tungsten (W) consists of five isotopes whose half-lives are so long that they can be considered stable. All can decay into isotopes of element 72 (hafnium) by alpha emission; 180W has been observed to have a half life of 1.8 +- 0.2 Ea. The other naturally occurring isotopes have not been observed to decay, constraining their half-lives to be: 182W, T1/2 > 8.3 Ea; 184W, T1/2 > 29 Ea; 185W, T1/2 > 13 Ea; 186W, T1/2 > 27 Ea. [National Nuclear Data Center table of nuclides, http://www.nndc.bnl.gov/chart/] On average, two alpha decays of 180W occur in one gram of natural tungsten per year.

27 artificial radioisotopes of tungsten have been characterized, the most stable of which are 181W with a half-life of 121.2 days, 185W with a half-life of 75.1 days, 188W with a half-life of 69.4 days and 178W with a half-life of 21.6 days. All of the remaining radioactive isotopes have half-lives of less than 24 hours, and most of these have half-lives that are less than 8 minutes. Tungsten also has 4 meta states, the most stable being 179mW (t½ 6.4 minutes).


Standard atomic mass: 183.84(1) u

Table

Notes

* Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
* Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.

References


* Isotope masses from [http://www.nndc.bnl.gov/amdc/index.html Ame2003 Atomic Mass Evaluation] by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in "Nuclear Physics" A729 (2003).
* Isotopic compositions and standard atomic masses from [http://www.iupac.org/publications/pac/2003/7506/7506x0683.html Atomic weights of the elements. Review 2000 (IUPAC Technical Report)] . "Pure Appl. Chem." Vol. 75, No. 6, pp. 683-800, (2003) and [http://www.iupac.org/news/archives/2005/atomic-weights_revised05.html Atomic Weights Revised (2005)] .
* Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
** Audi, Bersillon, Blachot, Wapstra. [http://amdc.in2p3.fr/web/nubase_en.html The Nubase2003 evaluation of nuclear and decay properties] , Nuc. Phys. A 729, pp. 3-128 (2003).
** National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the [http://www.nndc.bnl.gov/nudat2/ NuDat 2.1 database] (retrieved Sept. 2005).
** David R. Lide (ed.), Norman E. Holden in "CRC Handbook of Chemistry and Physics, 85th Edition", online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Tungsten — (pronEng|ˈtʌŋstən), also known as wolfram (IPA|/ˈwʊlfrəm/), is a chemical element that has the symbol W and atomic number 74.A steel gray metal, tungsten is found in several ores, including wolframite and scheelite. It is remarkable for its… …   Wikipedia

  • tungsten — tungstenic /tung sten ik/, adj. /tung steuhn/, n. Chem. a rare, metallic element having a bright gray color, a metallic luster, and a high melting point, 3410° C, and found in wolframite, tungstite, and other minerals: used in alloys of high… …   Universalium

  • List of fictional elements, materials, isotopes and atomic particles — This list contains chemical elements, materials, isotopes or (sub)atomic particle that exist primarily in works of fiction (usually fantasy or science fiction). No actual periodic elements end in ite , though many minerals have names with this… …   Wikipedia

  • Abundances of the isotopes — ▪ Table Abundances of the isotopes element Z symbol A abundance   mass excess hydrogen 1 H 1 99.9885 7.289 2 0.0151 13.136 helium 2 He 3 0.000138 14.931 4 99.999863 2.425 lithium 3 Li 6 7.59 14.086 7 92.41 14.908 beryllium 4 Be 9 100  11.348… …   Universalium

  • Table of nuclides — A chart of nuclides (cut into three parts for better presentation). A table of nuclides or chart of nuclides is a two dimensional graph in which one axis represents the number of neutrons and the other represents the number of protons in an… …   Wikipedia

  • Rhenium — tungsten ← rhenium → osmium Tc ↑ Re ↓ Bh …   Wikipedia

  • Molybdenum — niobium ← molybdenum → technetium Cr ↑ Mo ↓ W …   Wikipedia

  • Stable isotope — Graph of isotopes/nuclides by type of decay. Orange and blue nuclides are unstable, with the black squares between these regions representing stable nuclides. The unbroken line passing below many of the nuclides represents the theoretical… …   Wikipedia

  • Seaborgium — (pronEng|siːˈbɔrgiəm) is a chemical element in the periodic table that has the symbol Sg and atomic number 106, Image of Seaborgium . Seaborgium is a synthetic element whose most stable isotope 271Sg has a half life of 1.9 minutes. Chemistry… …   Wikipedia

  • Depleted uranium — The DU penetrator of a 30 mm round[1] Depleted uranium (DU; also referred to in the past as Q metal, depletalloy, or D 38) is uranium with a lower content of the fissile isotope U 235 than natural uranium (natural uranium is about 99.27% uranium… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.