Iodine-139

Properties and data of the isotope ¹³⁹I.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

See also: List of individual Iodine isotopes (and general data sources).

General data

Name of the isotope:Iodine-139; I-139Other names:Jod-139Symbol:¹³⁹I or 13953IMass number A:139 (= number of nucleons)Atomic number Z:53 (= number of protons)Neutrons N:86Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.622641509434 (= neutron-proton ratio)Neutron excess (N-Z):33Isotopic mass:138.926493(4) u (atomic weight of Iodine-139)Nuclide mass:138.8974201 u (calculated nuclear mass without electrons)Mass excess:-68.47133 MeVMass defect:1.233416472 u (per nucleus)Nuclear binding energy:1148.92004317 MeV (per nucleus)
8.26561182 MeV (average binding energy per nucleon)Separation energy:S_N = 4.562(7) MeV (first neutron)
S_P = 10.064(6) MeV (first proton)Half-life:2.280(11) sDecay constant λ:0.30401192129822 s^-1Specific activity α:1.326668560259 × 10⁺²¹ Bq g^-1
35855907034.035 Ci g^-1Spin and parity:
(nuclear angular momentum)(7/2+)Year of discovery:1949

Radioactive Decay

Half-life T_½ = 2.280(11) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹³⁹Xe	90 %	7.174(5) MeV
β^-, n	¹³⁸Xe	10.0(3) %	3.430(5) MeV

Parent Nuclides

Direct parent isotope is: ¹³⁹Te.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 86) and isobaric (same nucleon number A = 139) with Iodine-139. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 86	Isobar A = 139
48	¹³⁴Cd
49	¹³⁵In
50	¹³⁶Sn	¹³⁹Sn
51	¹³⁷Sb	¹³⁹Sb
52	¹³⁸Te	¹³⁹Te
53	¹³⁹I	¹³⁹I
54	¹⁴⁰Xe	¹³⁹Xe
55	¹⁴¹Cs	¹³⁹Cs
56	¹⁴²Ba	¹³⁹Ba
57	¹⁴³La	¹³⁹La
58	¹⁴⁴Ce	¹³⁹Ce
59	¹⁴⁵Pr	¹³⁹Pr
60	¹⁴⁶Nd	¹³⁹Nd
61	¹⁴⁷Pm	¹³⁹Pm
62	¹⁴⁸Sm	¹³⁹Sm
63	¹⁴⁹Eu	¹³⁹Eu
64	¹⁵⁰Gd	¹³⁹Gd
65	¹⁵¹Tb	¹³⁹Tb
66	¹⁵²Dy	¹³⁹Dy
67	¹⁵³Ho
68	¹⁵⁴Er
69	¹⁵⁵Tm
70	¹⁵⁶Yb
71	¹⁵⁷Lu
72	¹⁵⁸Hf
73	¹⁵⁹Ta
74	¹⁶⁰W
75	¹⁶¹Re
76	¹⁶²Os