Hafnium-172
Properties and data of the isotope 172Hf.
See also: List of individual Hafnium isotopes (and general data sources).
General data
Name of the isotope:Hafnium-172; Hf-172Symbol:172Hf or 17272HfMass number A:172 (= number of nucleons)Atomic number Z:72 (= number of protons)Neutrons N:100Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.3888888888889 (= neutron-proton ratio)Neutron excess (N-Z):28Isotopic mass:171.939450(26) u (atomic weight of Hafnium-172)Nuclide mass:171.899956 u (calculated nuclear mass without electrons)Mass excess:-56.40196 MeVMass defect:1.490443904 u (per nucleus)Nuclear binding energy:1388.33955391 MeV (per nucleus)
8.07174159 MeV (average binding energy per nucleon)Separation energy:SN = 9.04(4) MeV (first neutron)
SP = 5.863(24) MeV (first proton)Half-life:1.87(3) aDecay constant λ:1.175383538899 × 10-8 s-1Specific activity α:41393714828685 Bq g-1
1118.7490494239 Ci g-1Spin and parity:
(nuclear angular momentum)0+Charge radius:5.3065(43) femtometer fmYear of discovery:1951
Radioactive Decay
Half-life T½ = 1.87(3) a respectively 5.8972 × 107 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| EC | 172Lu | 100 % | 0.334(25) MeV | |
Parent Nuclides
Direct parent isotope is: 172Ta.
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 |
|---|
| 172mHf | 2005.84(11) keV | 163(3) ns | (8-) |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 100) and isobaric (same nucleon number A = 172) with Hafnium-172. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 100 | Isobar A = 172 |
|---|
| 57 | 157La | |
| 58 | 158Ce | |
| 59 | 159Pr | |
| 60 | 160Nd | |
| 61 | 161Pm | |
| 62 | 162Sm | |
| 63 | 163Eu | |
| 64 | 164Gd | 172Gd |
| 65 | 165Tb | 172Tb |
| 66 | 166Dy | 172Dy |
| 67 | 167Ho | 172Ho |
| 68 | 168Er | 172Er |
| 69 | 169Tm | 172Tm |
| 70 | 170Yb | 172Yb |
| 71 | 171Lu | 172Lu |
| 72 | 172Hf | 172Hf |
| 73 | 173Ta | 172Ta |
| 74 | 174W | 172W |
| 75 | 175Re | 172Re |
| 76 | 176Os | 172Os |
| 77 | 177Ir | 172Ir |
| 78 | 178Pt | 172Pt |
| 79 | 179Au | 172Au |
| 80 | 180Hg | 172Hg |
| 81 | 181Tl | |
| 82 | 182Pb | |
External data and identifiers
Last update: 2020-10-20
Perma link: https://www.chemlin.org/isotope/hafnium-172
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