Isotopes of iodine

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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

1 Medical applications
2 Table
- 2.1 Notes
3 References
4 External links

[edit] 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.^[1]

[edit] Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
nuclide symbol	excitation energy			half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
¹⁰⁸I	53	55	107.94348(39)#	36(6) ms	(1)#
¹⁰⁹I	53	56	108.93815(11)	103(5) µs	(5/2+)
¹¹⁰I	53	57	109.93524(33)#	650(20) ms	1+#
¹¹¹I	53	58	110.93028(32)#	2.5(2) s	(5/2+)#
¹¹²I	53	59	111.92797(23)#	3.42(11) s
¹¹³I	53	60	112.92364(6)	6.6(2) s	5/2+#
¹¹⁴I	53	61	113.92185(32)#	2.1(2) s	1+
^114mI	265.9(5) keV			6.2(5) s	(7)
¹¹⁵I	53	62	114.91805(3)	1.3(2) min	(5/2+)#
¹¹⁶I	53	63	115.91681(10)	2.91(15) s	1+
^116mI	400(50)# keV			3.27(16) µs	(7-)
¹¹⁷I	53	64	116.91365(3)	2.22(4) min	(5/2)+
¹¹⁸I	53	65	117.913074(21)	13.7(5) min	2-
^118mI	190.1(10) keV			8.5(5) min	(7-)
¹¹⁹I	53	66	118.91007(3)	19.1(4) min	5/2+
¹²⁰I	53	67	119.910048(19)	81.6(2) min	2-
^120m1I	72.61(9) keV			228(15) ns	(1+,2+,3+)
^120m2I	320(15) keV			53(4) min	(7-)
¹²¹I	53	68	120.907367(11)	2.12(1) h	5/2+
^121mI	2376.9(4) keV			9.0(15) µs
¹²²I	53	69	121.907589(6)	3.63(6) min	1+
¹²³I	53	70	122.905589(4)	13.2235(19) h	5/2+
¹²⁴I	53	71	123.9062099(25)	4.1760(3) d	2-
¹²⁵I	53	72	124.9046302(16)	59.400(10) d	5/2+
¹²⁶I	53	73	125.905624(4)	12.93(5) d	2-
¹²⁷I	53	74	126.904473(4)	STABLE	5/2+	1.0000
¹²⁸I	53	75	127.905809(4)	24.99(2) min	1+
^128m1I	137.850(4) keV			845(20) ns	4-
^128m2I	167.367(5) keV			175(15) ns	(6)-
¹²⁹I	53	76	128.904988(3)	1.57(4)E+7 a	7/2+
¹³⁰I	53	77	129.906674(3)	12.36(1) h	5+
^130m1I	39.9525(13) keV			8.84(6) min	2+
^130m2I	69.5865(7) keV			133(7) ns	(6)-
^130m3I	82.3960(19) keV			315(15) ns	-
^130m4I	85.1099(10) keV			254(4) ns	(6)-
¹³¹I	53	78	130.9061246(12)	8.02070(11) d	7/2+
¹³²I	53	79	131.907997(6)	2.295(13) h	4+
^132mI	104(12) keV			1.387(15) h	(8-)
¹³³I	53	80	132.907797(5)	20.8(1) h	7/2+
^133m1I	1634.174(17) keV			9(2) s	(19/2-)
^133m2I	1729.160(17) keV			~170 ns	(15/2-)
¹³⁴I	53	81	133.909744(9)	52.5(2) min	(4)+
^134mI	316.49(22) keV			3.52(4) min	(8)-
¹³⁵I	53	82	134.910048(8)	6.57(2) h	7/2+
¹³⁶I	53	83	135.91465(5)	83.4(10) s	(1-)
^136mI	650(120) keV			46.9(10) s	(6-)
¹³⁷I	53	84	136.917871(30)	24.13(12) s	(7/2+)
¹³⁸I	53	85	137.92235(9)	6.23(3) s	(2-)
¹³⁹I	53	86	138.92610(3)	2.282(10) s	7/2+#
¹⁴⁰I	53	87	139.93100(21)#	860(40) ms	(3)(-#)
¹⁴¹I	53	88	140.93503(21)#	430(20) ms	7/2+#
¹⁴²I	53	89	141.94018(43)#	~200 ms	2-#
¹⁴³I	53	90	142.94456(43)#	100# ms [>300 ns]	7/2+#
¹⁴⁴I	53	91	143.94999(54)#	50# ms [>300 ns]	1-#

[edit] 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.

[edit] References

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.

^ Erwann Rault, Stefaan Vandenberghe, Roel Van Holen, Jan De Beenhouwer, Steven Staelens, Ignace Lemahieu (2007). "Comparison of Image Quality of Different Iodine Isotopes (I-123, I-124, and I-131)" (abstract). Cancer Biotherapy & Radiopharmaceuticals 22 (3): 423–430. doi:10.1089/cbr.2006.323.