Praseodymium-129
Properties and data of the isotope 129Pr.
See also: List of individual Praseodymium isotopes (and general data sources).
General data
Name of the isotope:Praseodymium-129; Pr-129Symbol:129Pr or 12959PrMass number A:129 (= number of nucleons)Atomic number Z:59 (= number of protons)Neutrons N:70Isotopic mass:128.92509(3) u (atomic weight of Praseodymium-129)Nuclide mass:128.8927262 u (calculated nuclear mass without electrons)Mass excess:-69.77822 MeVMass defect:1.143131008 u (per nucleus)Nuclear binding energy:1064.81967517 MeV (per nucleus)
8.25441609 MeV (average binding energy per nucleon)Separation energy:SN = 11.51(4) MeV (first neutron)
SP = 1.53(4) MeV (first proton)Half-life:30(4) sDecay constant λ:0.023104906018665 s-1Specific activity α:1.087039051562 × 10+20 Bq g-1
2937943382.6014 Ci g-1Spin and parity:
(nuclear angular momentum)(3/2+)Year of discovery:1977
Radioactive Decay
Half-life T½ = 30(4) s respectively 3.0 × 101 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| EC/β+ | 129Ce | 100 % | 6.51(4) MeV | |
Parent Nuclides
Direct parent isotope is: 129Nd.
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 |
|---|
| 129mPr | 382.7(5) keV | 1~ ms | (11/2-) |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 70) and isobaric (same nucleon number A = 129) with Praseodymium-129. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 70 | Isobar A = 129 |
|---|
| 39 | 109Y | |
| 40 | 110Zr | |
| 41 | 111Nb | |
| 42 | 112Mo | |
| 43 | 113Tc | |
| 44 | 114Ru | |
| 45 | 115Rh | |
| 46 | 116Pd | 129Pd |
| 47 | 117Ag | 129Ag |
| 48 | 118Cd | 129Cd |
| 49 | 119In | 129In |
| 50 | 120Sn | 129Sn |
| 51 | 121Sb | 129Sb |
| 52 | 122Te | 129Te |
| 53 | 123I | 129I |
| 54 | 124Xe | 129Xe |
| 55 | 125Cs | 129Cs |
| 56 | 126Ba | 129Ba |
| 57 | 127La | 129La |
| 58 | 128Ce | 129Ce |
| 59 | 129Pr | 129Pr |
| 60 | 130Nd | 129Nd |
| 61 | 131Pm | 129Pm |
| 62 | 132Sm | 129Sm |
| 63 | 133Eu | |
| 64 | 134Gd | |
| 65 | 135Tb | |
External data and identifiers
Last update: 2020-10-19
Perma link: https://www.chemlin.org/isotope/praseodymium-129
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