To use all functions of this page, please activate cookies in your browser.
With an accout for my.chemeurope.com you can always see everything at a glance – and you can configure your own website and individual newsletter.
- My watch list
- My saved searches
- My saved topics
- My newsletter
Isotopes of lithium
Naturally occurring lithium is composed of two stable isotopes 6Li and 7Li, the latter being the more abundant (92.5% natural abundance). Seven radioisotopes have been characterized, the most stable being 8Li with a half-life of 838 ms and 9Li with a half-life of 178.3 ms. All of the remaining radioactive isotopes have half-lives that are shorter than 8.6 ms. The shortest-lived isotope of lithium is 4Li which decays through proton emission and has a half-life of 7.58043x10-23 s.
7Li is one of the primordial elements or, more properly, primordial isotopes, produced in Big Bang nucleosynthesis (a small amount of 6Li is also produced in stars). Lithium isotopes fractionate substantially during a wide variety of natural processes, including mineral formation (chemical precipitation), metabolism, and ion exchange. Lithium ion substitutes for magnesium and iron in octahedral sites in clay minerals, where 6Li is preferred to 7Li, resulting in enrichment of the light isotope in processes of hyperfiltration and rock alteration.
The exotic 11Li is known to exhibit a nuclear halo.
Additional recommended knowledge
Lithium-4 contains 3 protons and one neutron. It is the shortest lived isotope of lithium. It decays by proton emission and has a half-life of 9.1×10-23 s. It can be formed as an intermediate in some nuclear fusion reactions.
Some of the material remaining from the production of Lithium-6, which is depleted in Lithium-6 and enriched in Lithium-7, is made commercially available, and some has been released into the environment. Relative lithium-7 abundances as high as 35.4% greater than the natural value have been measured in ground water from a carbonate aquifer underlying West Valley Creek, Pennsylvania (USA), down-gradient from a lithium processing plant. In depleted material, the relative Li-6 abundance may be reduced by as much as 80 percent of its normal value, giving the atomic mass a range from 6.94 u to more than 6.99 u. As a result, the isotopic composition of lithium is highly variable depending on its source. An accurate relative atomic mass cannot be given representatively for all samples.
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes_of_lithium". A list of authors is available in Wikipedia.|