Tin-121m
Properties and data of the isotope 121mSn.
See also: List of individual Tin isotopes (and general data sources).
General data
Name of the isotope:Tin-121m; Sn-121mSymbol:121mSn or 121m50SnMass number A:121 (= number of nucleons)Atomic number Z:50 (= number of protons)Neutrons N:71Isotopic mass:120.9042428(10) u (atomic weight of Tin-121m)
Excitation energy: 6.31(6) keVNuclide mass:120.8768154 u (calculated nuclear mass without electrons)Mass excess:-89.19726 MeVMass defect:1.102217836 u (per nucleus)Nuclear binding energy:1026.70930093 MeV (per nucleus)
8.48520083 MeV (average binding energy per nucleon)Half-life:43.9(5) aDecay constant λ:5.006841812770 × 10-10 s-1Specific activity α:2512658888327.1 Bq g-1
67.909699684516 Ci g-1Spin and parity:
(nuclear angular momentum)11/2-Magnetic dipole moment:μ(μN) = - 1.3859(11)Quadrupole moment Q:- 0.14(3) barn (100 fm2)Nuclear g-factor:gl = -0.25198181818182
Radioactive Decay
Half-life T½ = 43.9(5) a respectively 1.3844 × 109 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| β- | 121Sb | 22.4(20) % | | |
| Iso | 121Sn | 77.6(20) % | | |
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 |
|---|
| 121Sn | | 27.03(4) h | 3/2+ |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 71) and isobaric (same nucleon number A = 121) with Tin-121m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 71 | Isobar A = 121 |
|---|
| 40 | 111Zr | |
| 41 | 112Nb | |
| 42 | 113Mo | |
| 43 | 114Tc | 121Tc |
| 44 | 115Ru | 121Ru |
| 45 | 116Rh | 121Rh |
| 46 | 117Pd | 121Pd |
| 47 | 118Ag | 121Ag |
| 48 | 119Cd | 121Cd |
| 49 | 120In | 121In |
| 50 | 121Sn | 121Sn |
| 51 | 122Sb | 121Sb |
| 52 | 123Te | 121Te |
| 53 | 124I | 121I |
| 54 | 125Xe | 121Xe |
| 55 | 126Cs | 121Cs |
| 56 | 127Ba | 121Ba |
| 57 | 128La | 121La |
| 58 | 129Ce | 121Ce |
| 59 | 130Pr | 121Pr |
| 60 | 131Nd | |
| 61 | 132Pm | |
| 62 | 133Sm | |
| 63 | 134Eu | |
| 64 | 135Gd | |
| 65 | 136Tb | |
Last update: 2020-10-17
Perma link: https://www.chemlin.org/isotope/tin-121m
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