Promethium-156
Properties and data of the isotope 156Pm.
See also: list of Promethium isotopes.
General data
Name of the isotope:Promethium-156; Pm-156Symbol:156Pm or 15661PmMass number A:156 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:95Isotopic mass:155.931117(4) u (atomic weight of Promethium-156)Nuclide mass:155.8976562 u (calculated nuclear mass without electrons)Mass excess:-64.1641 MeVMass defect:1.369376972 u (per nucleus)Nuclear binding energy:1275.56643316 MeV (per nucleus)
8.1767079 MeV (average binding energy per nucleon)Separation energy:SN = 5.295(6) MeV (first neutron)
SP = 9.169(10) MeV (first proton)Half-life:26.70(10) sDecay constant λ:0.025960568560298 s-1Specific activity α:1.008633552736 × 10+20 Bq g-1
2726036629.0176 Ci g-1Spin and parity:
(nuclear angular momentum)4(+)Year of discovery:1986
Radioactive Decay
Half-life T½ = 26.70(10) s respectively 2.670 × 101 seconds s.
Decay mode | Daughter | Probability | Decay energy | γ energy (intensity) |
---|
β- | 156Sm | 100 % | 5.197(9) MeV | |
Parent Nuclides
Direct parent isotope is: 156Nd.
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 95) and isobaric (same nucleon number A = 156) with Promethium-156. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
Z | Isotone N = 95 | Isobar A = 156 |
55 | 150Cs | |
56 | 151Ba | |
57 | 152La | 156La |
58 | 153Ce | 156Ce |
59 | 154Pr | 156Pr |
60 | 155Nd | 156Nd |
61 | 156Pm | 156Pm |
62 | 157Sm | 156Sm |
63 | 158Eu | 156Eu |
64 | 159Gd | 156Gd |
65 | 160Tb | 156Tb |
66 | 161Dy | 156Dy |
67 | 162Ho | 156Ho |
68 | 163Er | 156Er |
69 | 164Tm | 156Tm |
70 | 165Yb | 156Yb |
71 | 166Lu | 156Lu |
72 | 167Hf | 156Hf |
73 | 168Ta | 156Ta |
74 | 169W | 156W |
75 | 170Re | |
76 | 171Os | |
77 | 172Ir | |
78 | 173Pt | |
79 | 174Au | |
80 | 175Hg | |
81 | 176Tl | |
External data and identifiers
Last update: 2020-10-20
Perma link: https://www.chemlin.org/isotope/promethium-156
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