Thulium-172
Properties and data of the isotope 172Tm.
See also: List of individual Thulium isotopes (and general data sources).
General data
Name of the isotope:Thulium-172; Tm-172Symbol:172Tm or 17269TmMass number A:172 (= number of nucleons)Atomic number Z:69 (= number of protons)Neutrons N:103Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.4927536231884 (= neutron-proton ratio)Neutron excess (N-Z):34Isotopic mass:171.938406(6) u (atomic weight of Thulium-172)Nuclide mass:171.9005574 u (calculated nuclear mass without electrons)Mass excess:-57.37444 MeVMass defect:1.494007556 u (per nucleus)Nuclear binding energy:1391.65907437 MeV (per nucleus)
8.09104113 MeV (average binding energy per nucleon)Separation energy:SN = 6.235(5) MeV (first neutron)
SP = 6.944(5) MeV (first proton)Half-life:63.6(2) hDecay constant λ:3.027372381900 × 10-6 s-1Specific activity α:1.066155726274 × 10+16 Bq g-1
288150.1962903 Ci g-1Spin and parity:
(nuclear angular momentum)2-Charge radius:5.2411(52) femtometer fmYear of discovery:1956
Radioactive Decay
Half-life T½ = 63.6(2) h (hours) respectively 2.28960 × 105 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| β- | 172Yb | 100 % | 1.881(6) MeV | |
Parent Nuclides
Direct parent isotope is: 172Er.
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 |
|---|
| 172mTm | 476.2(2) keV | 132(7) μs | (6+) |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 103) and isobaric (same nucleon number A = 172) with Thulium-172. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 103 | Isobar A = 172 |
|---|
| 60 | 163Nd | |
| 62 | 165Sm | |
| 63 | 166Eu | |
| 64 | 167Gd | |
| 65 | 168Tb | 172Tb |
| 66 | 169Dy | 172Dy |
| 67 | 170Ho | 172Ho |
| 68 | 171Er | 172Er |
| 69 | 172Tm | 172Tm |
| 70 | 173Yb | 172Yb |
| 71 | 174Lu | 172Lu |
| 72 | 175Hf | 172Hf |
| 73 | 176Ta | 172Ta |
| 74 | 177W | 172W |
| 75 | 178Re | 172Re |
| 76 | 179Os | 172Os |
| 77 | 180Ir | 172Ir |
| 78 | 181Pt | 172Pt |
| 79 | 182Au | 172Au |
| 80 | 183Hg | 172Hg |
| 81 | 184Tl | |
| 82 | 185Pb | |
| 83 | 186Bi | |
| 84 | 187Po | |
| 85 | 188At | |
External data and identifiers
Last update: 2020-10-11
Perma link: https://www.chemlin.org/isotope/thulium-172
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