Thallium-188
Properties and data of the isotope 188Tl.
See also: List of individual Thallium isotopes (and general data sources).
General data
Name of the isotope:Thallium-188; Tl-188Symbol:188Tl or 18881TlMass number A:188 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:107Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.320987654321 (= neutron-proton ratio)Neutron excess (N-Z):26Isotopic mass:187.97602(3) u (atomic weight of Thallium-188)Nuclide mass:187.93159 u (calculated nuclear mass without electrons)Mass excess:-22.33723 MeVMass defect:1.584953604 u (per nucleus)Nuclear binding energy:1476.3747724 MeV (per nucleus)
7.8530573 MeV (average binding energy per nucleon)Separation energy:SN = 7.96(3) MeV (first neutron)
SP = 1.51(3) MeV (first proton)Half-life:71(2) sDecay constant λ:0.0097626363459147 s-1Specific activity α:3.143955681253 × 10+19 Bq g-1
849717751.69008 Ci g-1Spin and parity:
(nuclear angular momentum)(2-)Charge radius:5.4017(72) femtometer fmYear of discovery:1970
Radioactive Decay
Half-life T½ = 71(2) s respectively 7.1 × 101 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| EC/β+ | 188Hg | 100 % | 7.87(3) MeV | |
Parent Nuclides
Direct parent isotopes are: 192Bi, 188Pb.
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 |
|---|
| 188m1Tl | 35(31) keV | 71.5(15) s | (7+) |
| 188m2Tl | 303.8(2) keV | 41(4) ms | 9- |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 107) and isobaric (same nucleon number A = 188) with Thallium-188. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 107 | Isobar A = 188 |
|---|
| 65 | 172Tb | |
| 66 | 173Dy | |
| 67 | 174Ho | |
| 68 | 175Er | |
| 69 | 176Tm | |
| 70 | 177Yb | |
| 71 | 178Lu | 188Lu |
| 72 | 179Hf | 188Hf |
| 73 | 180Ta | 188Ta |
| 74 | 181W | 188W |
| 75 | 182Re | 188Re |
| 76 | 183Os | 188Os |
| 77 | 184Ir | 188Ir |
| 78 | 185Pt | 188Pt |
| 79 | 186Au | 188Au |
| 80 | 187Hg | 188Hg |
| 81 | 188Tl | 188Tl |
| 82 | 189Pb | 188Pb |
| 83 | 190Bi | 188Bi |
| 84 | 191Po | 188Po |
| 85 | 192At | 188At |
| 86 | 193Rn | |
External data and identifiers
Last update: 2020-10-22
Perma link: https://www.chemlin.org/isotope/thallium-188
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