Iodine-121m
Properties and data of the isotope 121I.
See also: list of Iodine isotopes.
General data
Name of the isotope:Iodine-121m; I-121mOther names:Jod-121mSymbol:121I or 12153IMass number A:121 (= number of nucleons)Atomic number Z:53 (= number of protons)Neutrons N:68Isotopic mass:120.907405(6) u (atomic weight of Iodine-121m)
Excitation energy: 2376.9(4) keVNuclide mass:120.8783321 u (calculated nuclear mass without electrons)Mass excess:-86.25169 MeVMass defect:1.096535984 u (per nucleus)Nuclear binding energy:1021.41668988 MeV (per nucleus)
8.44146025 MeV (average binding energy per nucleon)Half-life:9.0(14) μsDecay constant λ:77016.353395549 s-1Specific activity α:3.865027738888 × 10+26 Bq g-1
1.044602091591 × 10+16 Ci g-1Spin and parity:
(nuclear angular momentum)
Nuclear Isomers
Nuclear isomers or excited states with the activation energy in keV related to the ground state.
Nuclear Isomer | Excitation Energy | Half-life | Spin |
---|
121I | | 2.12(1) h | 5/2+ |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 68) and isobaric (same nucleon number A = 121) with Iodine-121m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
OZ | Isotone N = 68 | Isobar A = 121 |
38 | 106Sr | |
39 | 107Y | |
40 | 108Zr | |
41 | 109Nb | |
42 | 110Mo | |
43 | 111Tc | 121Tc |
44 | 112Ru | 121Ru |
45 | 113Rh | 121Rh |
46 | 114Pd | 121Pd |
47 | 115Ag | 121Ag |
48 | 116Cd | 121Cd |
49 | 117In | 121In |
50 | 118Sn | 121Sn |
51 | 119Sb | 121Sb |
52 | 120Te | 121Te |
53 | 121I | 121I |
54 | 122Xe | 121Xe |
55 | 123Cs | 121Cs |
56 | 124Ba | 121Ba |
57 | 125La | 121La |
58 | 126Ce | 121Ce |
59 | 127Pr | 121Pr |
60 | 128Nd | |
61 | 129Pm | |
62 | 130Sm | |
63 | 131Eu | |
Last update: 2020-10-18
Perma link: https://www.chemlin.org/isotope/iodine-121m
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