Promethium-140m
Properties and data of the isotope 140mPm.
See also: list of Promethium isotopes.
General data
Name of the isotope:Promethium-140m; Pm-140mSymbol:140mPm or 140m61PmMass number A:140 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:79Isotopic mass:139.916034(26) u (atomic weight of Promethium-140m)
Excitation energy: +x keVNuclide mass:139.8825732 u (calculated nuclear mass without electrons)Mass excess:-78.21383 MeVMass defect:1.245821316 u (per nucleus)Nuclear binding energy:1160.47508093 MeV (per nucleus)
8.28910772 MeV (average binding energy per nucleon)Half-life:5.95(5) minDecay constant λ:0.0019415887410643 s-1Specific activity α:8.411885532918 × 10+18 Bq g-1
227348257.64644 Ci g-1Spin and parity:
(nuclear angular momentum)8-
Radioactive Decay
Half-life T½ = 5.95(5) min (minutes) respectively 3.57 × 102 seconds s.
Decay mode | Daughter | Probability | Decay energy | γ energy (intensity) |
---|
EC/β+ | 140Nd | 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 |
---|
140Pm | | 9.2(2) s | 1+ |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 79) and isobaric (same nucleon number A = 140) with Promethium-140m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
Z | Isotone N = 79 | Isobar A = 140 |
44 | 123Ru | |
45 | 124Rh | |
46 | 125Pd | |
47 | 126Ag | |
48 | 127Cd | |
49 | 128In | |
50 | 129Sn | |
51 | 130Sb | 140Sb |
52 | 131Te | 140Te |
53 | 132I | 140I |
54 | 133Xe | 140Xe |
55 | 134Cs | 140Cs |
56 | 135Ba | 140Ba |
57 | 136La | 140La |
58 | 137Ce | 140Ce |
59 | 138Pr | 140Pr |
60 | 139Nd | 140Nd |
61 | 140Pm | 140Pm |
62 | 141Sm | 140Sm |
63 | 142Eu | 140Eu |
64 | 143Gd | 140Gd |
65 | 144Tb | 140Tb |
66 | 145Dy | 140Dy |
67 | 146Ho | 140Ho |
68 | 147Er | |
69 | 148Tm | |
70 | 149Yb | |
71 | 150Lu | |
External data and identifiers
Last update: 2020-10-20
Perma link: https://www.chemlin.org/isotope/promethium-140m
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