Promethium-136m
Properties and data of the isotope 136mPm.
See also: list of Promethium isotopes.
General data
Name of the isotope:Promethium-136m; Pm-136mSymbol:136mPm or 136m61PmMass number A:136 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:75Isotopic mass:135.92360(7) u (atomic weight of Promethium-136m)
Excitation energy: XNuclide mass:135.8901392 u (calculated nuclear mass without electrons)Mass excess:-71.16614 MeVMass defect:1.203595652 u (per nucleus)Nuclear binding energy:1121.14212826 MeV (per nucleus)
8.24369212 MeV (average binding energy per nucleon)Half-life:300(50) sDecay constant λ:0.0023104906018665 s-1Specific activity α:1.030674063703 × 10+19 Bq g-1
278560557.75776 Ci g-1Spin and parity:
(nuclear angular momentum)(2)
Radioactive Decay
Half-life T½ = 300(50) s respectively 3.00 × 102 seconds s.
Decay mode | Daughter | Probability | Decay energy | γ energy (intensity) |
---|
EC/β+ | 136Nd | 100 % | | |
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 |
---|
136Pm | Y | 107(6) s | (5-) |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 75) and isobaric (same nucleon number A = 136) with Promethium-136m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
Z | Isotone N = 75 | Isobar A = 136 |
42 | 117Mo | |
43 | 118Tc | |
44 | 119Ru | |
45 | 120Rh | |
46 | 121Pd | |
47 | 122Ag | |
48 | 123Cd | |
49 | 124In | 136In |
50 | 125Sn | 136Sn |
51 | 126Sb | 136Sb |
52 | 127Te | 136Te |
53 | 128I | 136I |
54 | 129Xe | 136Xe |
55 | 130Cs | 136Cs |
56 | 131Ba | 136Ba |
57 | 132La | 136La |
58 | 133Ce | 136Ce |
59 | 134Pr | 136Pr |
60 | 135Nd | 136Nd |
61 | 136Pm | 136Pm |
62 | 137Sm | 136Sm |
63 | 138Eu | 136Eu |
64 | 139Gd | 136Gd |
65 | 140Tb | 136Tb |
66 | 141Dy | |
67 | 142Ho | |
68 | 143Er | |
69 | 144Tm | |
External data and identifiers
Last update: 2020-10-20
Perma link: https://www.chemlin.org/isotope/promethium-136m
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