Iodine-129

Iodine-129, ¹²⁹I
General
Symbol	129I
Names	iodine-129, 129I, I-129
Protons (Z)	53
Neutrons (N)	76
Nuclide data
Natural abundance	Trace
Half-life (t1/2)	1.57×107 years
Isotope mass	128.904984 Da
Decay products	129Xe
Decay modes
Decay mode	Decay energy (MeV)
β−	0.189
	Isotopes of iodine ; Complete table of nuclides

Iodine-129 (¹²⁹I) is a long-lived radioisotope of iodine that occurs naturally but is also of special interest in the monitoring and effects of man-made nuclear fission products, where it serves as both a tracer and a potential radiological contaminant.

^ Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001.
^ Wang, M.; Audi, G.; Kondev, F. G.; Huang, W. J.; Naimi, S.; Xu, X. (2017). "The AME2016 atomic mass evaluation (II). Tables, graphs, and references" (PDF). Chinese Physics C. 41 (3): 030003-1–030003-442. doi:10.1088/1674-1137/41/3/030003.

[NUBASE2016-1] Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001.

[AME2016_II-2] Wang, M.; Audi, G.; Kondev, F. G.; Huang, W. J.; Naimi, S.; Xu, X. (2017). "The AME2016 atomic mass evaluation (II). Tables, graphs, and references" (PDF). Chinese Physics C. 41 (3): 030003-1–030003-442. doi:10.1088/1674-1137/41/3/030003.

[1]

[2]

General
Symbol	¹²⁹I
Names	iodine-129, 129I, I-129
Protons (Z)	53
Neutrons (N)	76
Nuclide data
Natural abundance	Trace
Half-life (t_1/2)	1.57×10⁷ years^[1]
Isotope mass	128.904984^[2] Da
Decay products	¹²⁹Xe
Decay modes
Decay mode	Decay energy (MeV)
β⁻	0.189
Isotopes of iodine Complete table of nuclides