Promethium-154m
Properties and data of the isotope 154mPm.
See also: list of Promethium isotopes.
General data
Name of the isotope:Promethium-154m; Pm-154mSymbol:154mPm or 154m61PmMass number A:154 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:93Isotopic mass:153.92645(5) u (atomic weight of Promethium-154m)
Excitation energy: +x keVNuclide mass:153.8929892 u (calculated nuclear mass without electrons)Mass excess:-68.51138 MeVMass defect:1.35671414 u (per nucleus)Nuclear binding energy:1263.77108113 MeV (per nucleus)
8.20630572 MeV (average binding energy per nucleon)Half-life:1.73(10) minDecay constant λ:0.0066777185025043 s-1Specific activity α:2.628376565038 × 10+19 Bq g-1
710372044.60495 Ci g-1Spin and parity:
(nuclear angular momentum)(0-.1-)
Radioactive Decay
Half-life T½ = 1.73(10) min (minutes) respectively 1.038 × 102 seconds s.
Decay mode | Daughter | Probability | Decay energy | γ energy (intensity) |
---|
β- | 154Sm | 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 |
---|
154Pm | | 2.68(7) min | (3,4) |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 93) and isobaric (same nucleon number A = 154) with Promethium-154m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
Z | Isotone N = 93 | Isobar A = 154 |
54 | 147Xe | |
55 | 148Cs | |
56 | 149Ba | |
57 | 150La | 154La |
58 | 151Ce | 154Ce |
59 | 152Pr | 154Pr |
60 | 153Nd | 154Nd |
61 | 154Pm | 154Pm |
62 | 155Sm | 154Sm |
63 | 156Eu | 154Eu |
64 | 157Gd | 154Gd |
65 | 158Tb | 154Tb |
66 | 159Dy | 154Dy |
67 | 160Ho | 154Ho |
68 | 161Er | 154Er |
69 | 162Tm | 154Tm |
70 | 163Yb | 154Yb |
71 | 164Lu | 154Lu |
72 | 165Hf | 154Hf |
73 | 166Ta | |
74 | 167W | |
75 | 168Re | |
76 | 169Os | |
77 | 170Ir | |
78 | 171Pt | |
79 | 172Au | |
80 | 173Hg | |
External data and identifiers
Last update: 2020-10-20
Perma link: https://www.chemlin.org/isotope/promethium-154m
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