Promethium-149
Properties and data of the isotope 149Pm.
See also: List of individual Promethium isotopes (and general data sources).
General data
Name of the isotope:Promethium-149; Pm-149Symbol:149Pm or 14961PmMass number A:149 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:88Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.4426229508197 (= neutron-proton ratio)Neutron excess (N-Z):27Isotopic mass:148.9183417(24) u (atomic weight of Promethium-149)Nuclide mass:148.8848809 u (calculated nuclear mass without electrons)Mass excess:-76.06422 MeVMass defect:1.32149786 u (per nucleus)Nuclear binding energy:1230.9673276 MeV (per nucleus)
8.26152569 MeV (average binding energy per nucleon)Separation energy:SN = 7.270(6) MeV (first neutron)
SP = 5.9452(24) MeV (first proton)Half-life:53.08(5) hDecay constant λ:3.627371580423 × 10-6 s-1Specific activity α:1.47598260869 × 10+16 Bq g-1
398914.21856541 Ci g-1Spin and parity:
(nuclear angular momentum)7/2+Magnetic dipole moment:μ(μN) = 3.3(5)Nuclear g-factor:gl = 0.94285714285714Year of discovery:1947
Radioactive Decay
Half-life T½ = 53.08(5) h (hours) respectively 1.91088 × 105 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| β- | 149Sm | 100 % | 1.0715(19) MeV | |
Parent Nuclides
Direct parent isotope is: 149Nd.
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 88) and isobaric (same nucleon number A = 149) with Promethium-149. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 88 | Isobar A = 149 |
|---|
| 49 | 137In | |
| 50 | 138Sn | |
| 51 | 139Sb | |
| 52 | 140Te | |
| 53 | 141I | |
| 54 | 142Xe | |
| 55 | 143Cs | 149Cs |
| 56 | 144Ba | 149Ba |
| 57 | 145La | 149La |
| 58 | 146Ce | 149Ce |
| 59 | 147Pr | 149Pr |
| 60 | 148Nd | 149Nd |
| 61 | 149Pm | 149Pm |
| 62 | 150Sm | 149Sm |
| 63 | 151Eu | 149Eu |
| 64 | 152Gd | 149Gd |
| 65 | 153Tb | 149Tb |
| 66 | 154Dy | 149Dy |
| 67 | 155Ho | 149Ho |
| 68 | 156Er | 149Er |
| 69 | 157Tm | 149Tm |
| 70 | 158Yb | 149Yb |
| 71 | 159Lu | 149Lu |
| 72 | 160Hf | |
| 73 | 161Ta | |
| 74 | 162W | |
| 75 | 163Re | |
| 76 | 164Os | |
| 77 | 165Ir | |
| 78 | 166Pt | |
External data and identifiers
Last update: 2020-10-20
Perma link: https://www.chemlin.org/isotope/promethium-149
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