Hafnium-161
Properties and data of the isotope 161Hf.
See also: List of individual Hafnium isotopes (and general data sources).
General data
Name of the isotope:Hafnium-161; Hf-161Symbol:161Hf or 16172HfMass number A:161 (= number of nucleons)Atomic number Z:72 (= number of protons)Neutrons N:89Isotopic mass:160.950279(24) u (atomic weight of Hafnium-161)Nuclide mass:160.910785 u (calculated nuclear mass without electrons)Mass excess:-46.31481 MeVMass defect:1.384300828 u (per nucleus)Nuclear binding energy:1289.46791548 MeV (per nucleus)
8.00911749 MeV (average binding energy per nucleon)Separation energy:SN = 8.447(24) MeV (first neutron)
SP = 3.33(6) MeV (first proton)Half-life:18.4(4)sDecay constant λ:0.037671042421736 s-1Specific activity α:1.417877023777 × 10+20 Bq g-1
3832100064.2627 Ci g-1Spin and parity:
(nuclear angular momentum)(7/2-)Year of discovery:1973
Radioactive Decay
Half-life T½ = 18.4(4)s respectively 1.84 × 101 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| EC/β+ | 161Lu | > 99.87 % | 6.25(4) MeV | |
| α | 157Yb | < 0.13 % | 4.682(24) MeV | |
Parent Nuclides
Direct parent isotope is: 165W.
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 |
|---|
| 161mHf | 329.0(5) keV | 4.8(2) μs | (13/2+) |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 89) and isobaric (same nucleon number A = 161) with Hafnium-161. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 89 | Isobar A = 161 |
|---|
| 50 | 139Sn | |
| 51 | 140Sb | |
| 52 | 141Te | |
| 53 | 142I | |
| 54 | 143Xe | |
| 55 | 144Cs | |
| 56 | 145Ba | |
| 57 | 146La | |
| 58 | 147Ce | |
| 59 | 148Pr | |
| 60 | 149Nd | 161Nd |
| 61 | 150Pm | 161Pm |
| 62 | 151Sm | 161Sm |
| 63 | 152Eu | 161Eu |
| 64 | 153Gd | 161Gd |
| 65 | 154Tb | 161Tb |
| 66 | 155Dy | 161Dy |
| 67 | 156Ho | 161Ho |
| 68 | 157Er | 161Er |
| 69 | 158Tm | 161Tm |
| 70 | 159Yb | 161Yb |
| 71 | 160Lu | 161Lu |
| 72 | 161Hf | 161Hf |
| 73 | 162Ta | 161Ta |
| 74 | 163W | 161W |
| 75 | 164Re | 161Re |
| 76 | 165Os | 161Os |
| 77 | 166Ir | |
| 78 | 167Pt | |
External data and identifiers
Last update: 2020-10-20
Perma link: https://www.chemlin.org/isotope/hafnium-161
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