Isotopes of iodine

Isotopes of iodine

There are 37 isotopes of iodine (I) and only one, 127I, is stable.

In many ways, 129I is similar to 36Cl. It is a soluble halogen, fairly non-reactive, exists mainly as a non-sorbing anion, and is produced by cosmogenic, thermonuclear, and in-situ reactions. In hydrologic studies, 129I concentrations are usually reported as the ratio of 129I to total I (which is virtually all 127I). As is the case with 36Cl/Cl, 129I/I ratios in nature are quite small, 10−14 to 10−10 (peak thermonuclear 129I/I during the 1960s and 1970s reached about 10−7). 129I differs from 36Cl in that its half-life is longer (15.7 vs. 0.301 million years), it is highly biophilic, and occurs in multiple ionic forms (commonly, I and IO3) which have different chemical behaviors. This makes it fairly easy for 129I to enter the biosphere as it becomes incorporated into vegetation, soil, milk, animal tissue, etc.

Excesses of stable 129Xe in meteorites have been shown to result from decay of "primordial" 129I produced newly by the supernovas which created the dust and gas from which the solar system formed. 129I was the first extinct radionuclide to be identified as present in the early solar system. Its decay is the basis of the I-Xe radiometric dating scheme, which covers the first 83 million years of solar system evolution.
Standard atomic mass: 126.90447(3) u

Medical applications

A number of the iodine isotopes are used as radioisotopes in nuclear medicine:
iodine-123 and iodine-131 is used for single photon emission computed tomography (SPECT) imaging and iodine-124 for positron emission tomography.They may result in different image quality. [Cite journal
author = Erwann Rault, Stefaan Vandenberghe, Roel Van Holen, Jan De Beenhouwer, Steven Staelens, Ignace Lemahieu
title = Comparison of Image Quality of Different Iodine Isotopes (I-123, I-124, and I-131)
journal = Cancer Biotherapy & Radiopharmaceuticals
year = 2007
volume = 22
issue = 3
pages = 423–430
url =
doi = 10.1089/cbr.2006.323
format = abstract



* 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.


* Isotope masses from [ 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 [ Atomic weights of the elements. Review 2000 (IUPAC Technical Report)] . "Pure Appl. Chem." Vol. 75, No. 6, pp. 683-800, (2003) and [ 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. [ 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 [ 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.

External links

* [ Iodine isotopes data from "The Berkeley Laboratory Isotopes Project's"]

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Iodine (disambiguation) — Iodine is a chemical element.Iodine may also refer to:*Isotopes of iodine: **Iodine 123 **Iodine 124 **Iodine 125 **Iodine 129 **Iodine 131*Iodine clock reaction *Iodine deficiency *Iodine Recordings *Iodine test *Iodine value *Tincture of… …   Wikipedia

  • Iodine-123 — (123I) is a radioactive isotope of iodine used in nuclear medicine imaging, including single photon emission computed tomography (SPECT). Iodine 123 is produced in a cyclotron by proton irradiation of enriched xenon. Its half life is 13.22 hours; …   Wikipedia

  • Iodine-124 — or 124I is an isotope of iodine. This isotope is not stable and therefore is radioactive, also called a radioisotope. It has a half life of 4.18 days. Modes of Decay: 74.4% electron capture, 25.6% positron emission. 124I decays to… …   Wikipedia

  • Iodine-131 — Infobox isotope alternate names =Radioiodine symbol =I mass number =131 mass = num neutrons =78 num protons =53 abundance = halflife =8.0197 days error halflife = background =#c9F text color = decay product = decay symbol = decay mass = decay… …   Wikipedia

  • Isotopes of caesium — Caesium (Cs) has 40 known isotopes. The atomic masses of these isotopes range from 112 to 151. Only one isotope, 133Cs, is stable. The longest lived radioisotopes are 135Cs with a half life of 2.3 million years, 137Cs with a half life of 30.1671… …   Wikipedia

  • Iodine — (IPAEng|ˈaɪədaɪn, ˈaɪədɪn, or IPA|/ˈaɪədiːn/; from el. ιώδης iodes violet ), is a chemical element that has the symbol I and atomic number 53. Naturally occurring iodine is a single isotope with 74 neutrons. Chemically, iodine is the least… …   Wikipedia

  • Iodine-129 — (129I) is a radioisotope of iodine. Formation and decay129I is primarily formed from the fission of uranium and plutonium in nuclear reactors. Significant amounts were released into the atmosphere as a result of nuclear weapons testing in the… …   Wikipedia

  • Iodine-125 — (125I) is a radioisotope of iodine which has uses in biological assays and in radiation therapy to treat prostate cancer and brain tumors. Its half life is around 60 days and it emits gamma rays with maximum energies of 35 keV, some of which are… …   Wikipedia

  • iodine — Symbol: I Atomic number: 53 Atomic weight: 126.904 Dark violet nonmetallic element, belongs to group 17 of the periodic table. Insoluble in water. Required as a trace element for living organisms. One stable isotope, I 127 exists, in addition to… …   Elements of periodic system

  • Commonly used gamma emitting isotopes — Radionuclides which emit gamma radiation are valuable in a range of different industrial, scientific and medical technologies. This article lists some common gamma emitting radionuclides of technological importance, and their properties. Contents …   Wikipedia