Iodine-137
Properties and data of the isotope 137I.
See also: List of individual Iodine isotopes (and general data sources).
General data
Name of the isotope:Iodine-137; I-137Other names:Jod-137Symbol:137I or 13753IMass number A:137 (= number of nucleons)Atomic number Z:53 (= number of protons)Neutrons N:84Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.5849056603774 (= neutron-proton ratio)Neutron excess (N-Z):31Isotopic mass:136.918028(9) u (atomic weight of Iodine-137)Nuclide mass:136.8889551 u (calculated nuclear mass without electrons)Mass excess:-76.35643 MeVMass defect:1.22455164 u (per nucleus)Nuclear binding energy:1140.66250535 MeV (per nucleus)
8.32600369 MeV (average binding energy per nucleon)Separation energy:SN = 4.882(16) MeV (first neutron)
SP = 9.220(9) MeV (first proton)Half-life:24.5(2) sDecay constant λ:0.028291721655508 s-1Specific activity α:1.252770095438 × 10+20 Bq g-1
3385865122.8059 Ci g-1Spin and parity:
(nuclear angular momentum)(7/2+)Year of discovery:1943
Radioactive Decay
Half-life T½ = 24.5(2) s respectively 2.45 × 101 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| β- | 137Xe | 92.86 % | 6.027(8) MeV | |
| β-, n | 136Xe | 7.14 % | 2.002(8) MeV | |
Parent Nuclides
Direct parent isotopes are: 137Te, 248Cm.
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 84) and isobaric (same nucleon number A = 137) with Iodine-137. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 84 | Isobar A = 137 |
|---|
| 47 | 131Ag | |
| 48 | 132Cd | |
| 49 | 133In | 137In |
| 50 | 134Sn | 137Sn |
| 51 | 135Sb | 137Sb |
| 52 | 136Te | 137Te |
| 53 | 137I | 137I |
| 54 | 138Xe | 137Xe |
| 55 | 139Cs | 137Cs |
| 56 | 140Ba | 137Ba |
| 57 | 141La | 137La |
| 58 | 142Ce | 137Ce |
| 59 | 143Pr | 137Pr |
| 60 | 144Nd | 137Nd |
| 61 | 145Pm | 137Pm |
| 62 | 146Sm | 137Sm |
| 63 | 147Eu | 137Eu |
| 64 | 148Gd | 137Gd |
| 65 | 149Tb | 137Tb |
| 66 | 150Dy | |
| 67 | 151Ho | |
| 68 | 152Er | |
| 69 | 153Tm | |
| 70 | 154Yb | |
| 71 | 155Lu | |
| 72 | 156Hf | |
| 73 | 157Ta | |
| 74 | 158W | |
| 75 | 159Re | |
| 76 | 160Os | |
External data and identifiers
Literature and References
[1] - R. C. Greenwood, K. D. Watts:
Delayed Neutron Energy Spectra of 87Br, 88Br, 89Br, 90Br, 137I, 138I, 139I, and 136Te.
In: Nuclear Science and Engineering, Volume 126, (2017), DOI 10.13182/NSE97-A24484.
Last update: 2023-04-27
Perma link: https://www.chemlin.org/isotope/iodine-137
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