Tellurium isotope

At least 21 tellurium isotopes are known, with mass numbers from 114 to 134. Of these, eight are stable, ie, 120, 122—126, 128, 130. The others are radioactive and have lifetimes from 2 min to 154 d the heaviest six, 131m, 131,132, 133m, 133, and 134, are fission products (see Radioisotopes). 

Eighteen isotopes of sulfur, 17 of selenium, 21 of tellurium, and 27 of polonium have been registered of these, 4 sulfur, 6 selenium, and 8 tellurium isotopes are stable, while there is no stable isotope of polonium. None of the naturally occurring isotopes of Se is radioactive its radioisotopes are by-products of the nuclear reactor and neutron activation technology. The naturally occurring, stable isotopes of S, Se, and Te are included in Table 1.2. 

The silver white, shiny, metal-like semiconductor is considered a semimetal. The atomic weight is greater than that of the following neighbor (iodine), because tellurium isotopes are neutron-rich (compare Ar/K). Its main use is in alloys, as the addition of small amounts considerably improves properties such as hardness and corrosion resistance. New applications of tellurium include optoelectronics (lasers), electrical resistors, thermoelectric elements (a current gives rise to a temperature gradient), photocopier drums, infrared cameras, and solar cells. Tellurium accelerates the vulcanization of rubber. 

Enriched or should be used for the reactor irradiation to eliminate unwanted background radiations from the other tellurium isotopes. Radiation damage to the source is unimportant since annealing (13) the ZnTe after irradiation did not change line intensity or width. 

Kirsten, T., Heusser, E., Kaether, D., Oehm, I, Pernicka, E., Richter, H. (1986) New geochemical double beta decay measurements on various selenium ores and remarks concerning tellurium isotopes. In Nuclear Beta Decays and Neutrino, T. Kotani, E. Ejiri, E. Takasugi, Eds., pp. 81-92. Singapore World Scientific. 

The light and heavy isotope enrichment in Xe-HL has been interpreted as being due to the p- and r-process, and thus requires an SN origin (Heymann and Dziczkaniec, 1979, 1980 Clayton, 1989). In one model, Xe-H is made by a short neutron burst, with neutron densities intermediate between those characteristic for the r- and s-processes (Clayton, 1989 Howard et al., 1992). Ott (1996) kept the standard r-process but proposed that xenon is separated from iodine and tellurium precursors on a timescale of a few hours after their production. Measurements of tellurium isotopes in nanodiamonds show almost complete absence of the isotopes Te, 22-i26rj,g ... 

We include parameters found in recent investigations of near-magic isotopes, for example, antimony and tellurium isotopes which have one and two valence protons above the closed Z = 50 proton shell. The systematic character of trends in positions of low-lying levels of heavy isotopes was noticed by many authors. The linear trend in positions of low-lying levels in heavy A-odd isotopes is shown in Table 3. 

The radioactive tellurium isotopes decay to their isobaric iodine daughter products. This means that from each location where tellurium deposits have formed, radioactive iodine isotopes will be released to the steam flow. However, the magnitude of these iodine sources can be assumed to be small compared to the direct volatilization of iodine from the fuel. Thus, they can usually be ignored when evaluating iodine input into the containment, with the only exception possibly being the short-lived... 

Fehr, M.A., Rebkamper, M., Halliday, A.N., Wiechert, U., Hattendorf, B., Gunther, D., Ono, S., Eigenbrode, J.L., and Rumble, D. Ill (2005) Tellurium isotopic composition in the early solar system - a search for effects resulting from stellar nucleosynthesis, Sn decay, and mass-independent fractionation. Ceochim. Cosmochim. 

The tellurium isotope was made by the fission of "U, with an enriched uranium (>90% U)-aluminum alloy usually serving as the target (133). The isomer 131mTe (30-h) is also produced and gives rise to The "Te/ Te ratio... 

Thirty isotopes of tellurium are known, with atomic masses ranging from 108 to 137. Natural tellurium consists of eight isotopes. 

Gases and vapors of volatile liquids can be introduced directly into a plasma flame for elemental analysis or for isotope ratio measurements. Some elements can be examined by first converting them chemically into volatile forms, as with the formation of hydrides of arsenic and tellurium. It is important that not too much analyte pass into the flame, as the extra material introduced into the plasma can cause it to become unstable or even to go out altogether, thereby compromising accuracy or continuity of measurement. 

Tellurium illustrates the rule that elements having even atomic numbers have more isotopes than elements having odd atomic numbers. 

Antimony [7440-36-0J, Sb, belongs to Group 15 (VA) of the periodic table which also includes the elements arsenic and bismuth. It is in the second long period of the table between tin and tellurium. Antimony, which may exhibit a valence of +5, +3, 0, or —3 (see Antimony compounds), is classified as a nonmetal or metalloid, although it has metallic characteristics in the trivalent state. There are two stable antimony isotopes that ate both abundant and have masses of 121 (57.25%) and 123 (42.75%). 

The only sulfur isotope with a nuclear spin is which is quadrupolar (/ = 3/2) and of low natural abundance (0.76%). In view of these inherent difficulties and the low symmetry around the sulfur nuclei in most S-N compounds, S NMR spectroscopy has found very limited application in S-N chemistry. However, it is likely that reasonably narrow resonances could be obtained for sulfur in a tetrahedral environment, e.g. [S(N Bu)4], cf. [S04] . On the other hand both selenium and tellurium have isotopes with I = Vi with significant natural abundances ( Se, 7.6% and Te, 7.0%). Consequently, NMR studies using these nuclei can provide useful information for Se-N and Te-N systems. 

Table 1.2 Naturally occurring, stable isotopes of sulfur, selenium, and tellurium...

Te is an excellent candidate for the search of DBD because of its high transition energy (2528.8 1.3 keV [95]), its great isotopic abundance in natural tellurium (33.80 0.01% [96]) and its relatively high Debye temperature ( 232K) [97],... 

The chemistry of sulfur is a broad area that includes such chemicals as sulfuric acid (the compound prepared in the largest quantity) as well as unusual compounds containing nitrogen, phosphorus, and halogens. Although there is an extensive chemistry of selenium and tellurium, much of it follows logically from the chemistry of sulfur if allowance is made for the more metallic character of the heavier elements. All isotopes of polonium are radioactive, and compounds of the element are not items of commerce or great use. Therefore, the chemistry of sulfur will be presented in more detail. 

The most widely used radio-isotope, iodine-131, is prepared in this way (S3), (55), (59), (69), (96). It is produced in the atomic reactor by bombardment of tellurium, one of the isotopes of which decays by -emission to iodine 131 ... 

Lee DC, Halliday AN (1995) Precise determinations of the isotopic compositions and atomic weights of molybdenum, tellurium, tin and tungsten using ICP magnetic-sector multiple collector mass-spectrometry. Int J Mass Spectr Ion Proc 146 35-46... 

Magnetic Hyperfine Structure. The magnetic fields in most magnetic iodine and tellurium compounds are not sufficient to separate the 18 magnetic hyperfine lines of the two iodine isotopes. Several measurements (13, 21, 34, 36) have indicated that fields of only about 100 kilo-gauss can be expected from such compounds. Therefore, other methods must be utilized. 

ISOTOPES There are a total of 48 isotopes of tellurium. Eight of these are considered stable. Three of the stable ones are actually radioactive but have such long half-lives that they still contribute to the natural abundance of tellurium in the crust of the Earth. The isotope Te-123 (half-life of 6x10+ " years) contributes 0.89% of the total tellurium found on Earth, Te-128 (half-life of 7.7x 10 years) contributes 31.74% to the natural abundance, and Te-130 (half-life of 0.79x10+ years) contributes 34.08% to the tellurium in the Earth s crust. The other five stable isotopes and the percentage of their natural abundance are as follows Te-120 = 0.09%, Te-122 = 2.55%, Te-124 = 4.74%, Te-125 = 7.07%, and Te-126 = 18.84%. The other 40 isotopes are all radioactive with short half-lives. 

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