Thallium-186
Properties and data of the isotope 186Tl.
See also: List of individual Thallium isotopes (and general data sources).
General data
Name of the isotope:Thallium-186; Tl-186Symbol:186Tl or 18681TlMass number A:186 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:105Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.2962962962963 (= neutron-proton ratio)Neutron excess (N-Z):24Isotopic mass:185.978651(24) u (atomic weight of Thallium-186)Nuclide mass:185.934221 u (calculated nuclear mass without electrons)Mass excess:-19.88647 MeVMass defect:1.564992772 u (per nucleus)Nuclear binding energy:1457.78137716 MeV (per nucleus)
7.83753429 MeV (average binding energy per nucleon)Separation energy:SN = 8.20(3) MeV (first neutron)
SP = 0.992(26) MeV (first proton)Half-life:27.5(10) sDecay constant λ:0.025205352020362 s-1Specific activity α:8.204874610319 × 10+19 Bq g-1
2217533678.4647 Ci g-1Spin and parity:
(nuclear angular momentum)(7+)Magnetic dipole moment:μ(μN) = 0.497(9)Quadrupole moment Q:0.06(1) barn (100 fm2)Nuclear g-factor:gl = 0.071Year of discovery:1975
Radioactive Decay
Half-life T½ = 27.5(10) s respectively 2.75 × 101 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| EC/β+ | 186Hg | ca. 100 % | 8.652(25) MeV | |
| α | 182Au | 0.006 % | 5.99(3) MeV | |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 105) and isobaric (same nucleon number A = 186) with Thallium-186. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 105 | Isobar A = 186 |
|---|
| 63 | 168Eu | |
| 64 | 169Gd | |
| 65 | 170Tb | |
| 66 | 171Dy | |
| 67 | 172Ho | |
| 68 | 173Er | |
| 69 | 174Tm | |
| 70 | 175Yb | |
| 71 | 176Lu | 186Lu |
| 72 | 177Hf | 186Hf |
| 73 | 178Ta | 186Ta |
| 74 | 179W | 186W |
| 75 | 180Re | 186Re |
| 76 | 181Os | 186Os |
| 77 | 182Ir | 186Ir |
| 78 | 183Pt | 186Pt |
| 79 | 184Au | 186Au |
| 80 | 185Hg | 186Hg |
| 81 | 186Tl | 186Tl |
| 82 | 187Pb | 186Pb |
| 83 | 188Bi | 186Bi |
| 84 | 189Po | 186Po |
| 85 | 190At | |
External data and identifiers
Last update: 2020-10-22
Perma link: https://www.chemlin.org/isotope/thallium-186
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