Thallium-177m
Properties and data of the isotope 177mTl.
See also: List of individual Thallium isotopes (and general data sources).
General data
Name of the isotope:Thallium-177m; Tl-177mSymbol:177mTl or 177m81TlMass number A:177 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:96Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.1851851851852 (= neutron-proton ratio)Neutron excess (N-Z):15Excitation energy:807(23) keVIsotopic mass:176.996414(23) u (atomic weight of Thallium-177m)Nuclide mass:176.951984 u (calculated nuclear mass without electrons)Mass excess:-3.34034 MeVMass defect:1.469245528 u (per nucleus)Nuclear binding energy:1368.59339386 MeV (per nucleus)
7.73216607 MeV (average binding energy per nucleon)Half-life:230(40) μsDecay constant λ:3013.6833937389 s-1Specific activity α:1.031183290019 × 10+25 Bq g-1
2.786981864918 × 10+14 Ci g-1Spin and parity:
(nuclear angular momentum)(11/2-)
Radioactive Decay
Half-life T½ = 230(40) μs respectively 2.30 × 10-4 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| p | 176Hg | 51(8) % | | |
| α | 173Au | 49(8) % | | |
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 |
|---|
| 177Tl | | 18(5) ms | (1/2+) |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 96) and isobaric (same nucleon number A = 177) with Thallium-177m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 96 | Isobar A = 177 |
|---|
| 55 | 151Cs | |
| 56 | 152Ba | |
| 57 | 153La | |
| 58 | 154Ce | |
| 59 | 155Pr | |
| 60 | 156Nd | |
| 61 | 157Pm | |
| 62 | 158Sm | |
| 63 | 159Eu | |
| 64 | 160Gd | |
| 65 | 161Tb | |
| 66 | 162Dy | |
| 67 | 163Ho | |
| 68 | 164Er | 177Er |
| 69 | 165Tm | 177Tm |
| 70 | 166Yb | 177Yb |
| 71 | 167Lu | 177Lu |
| 72 | 168Hf | 177Hf |
| 73 | 169Ta | 177Ta |
| 74 | 170W | 177W |
| 75 | 171Re | 177Re |
| 76 | 172Os | 177Os |
| 77 | 173Ir | 177Ir |
| 78 | 174Pt | 177Pt |
| 79 | 175Au | 177Au |
| 80 | 176Hg | 177Hg |
| 81 | 177Tl | 177Tl |
| 82 | 178Pb | |
Last update: 2020-10-22
Perma link: https://www.chemlin.org/isotope/thallium-177m
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