Thallium-178
Properties and data of the isotope 178Tl.
See also: List of individual Thallium isotopes (and general data sources).
General data
Name of the isotope:Thallium-178; Tl-178Symbol:178Tl or 17881TlMass number A:178 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:97Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.1975308641975 (= neutron-proton ratio)Neutron excess (N-Z):16Isotopic mass:177.99486(10) u (atomic weight of Thallium-178)Nuclide mass:177.95043 u (calculated nuclear mass without electrons)Mass excess:-4.78788 MeVMass defect:1.479464444 u (per nucleus)Nuclear binding energy:1378.1122528 MeV (per nucleus)
7.74220367 MeV (average binding energy per nucleon)Separation energy:SN = 9.52(9) MeV (first neutron)Half-life:ca. 254 msDecay constant λ:2.7289259077163 s-1Specific activity α:9.284732323501 × 10+21 Bq g-1
250938711446 Ci g-1Spin and parity:
(nuclear angular momentum)Year of discovery:1997
Radioactive Decay
Half-life T½ = ca. 254 ms respectively 2.54 × 10-1 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| α | 174Au | ca. 53 % | 7.02(1) MeV | |
| EC/β+ | 178Hg | ca. 47 % | 11.53(9) MeV | |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 97) and isobaric (same nucleon number A = 178) with Thallium-178. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 97 | Isobar A = 178 |
|---|
| 56 | 153Ba | |
| 57 | 154La | |
| 58 | 155Ce | |
| 59 | 156Pr | |
| 60 | 157Nd | |
| 61 | 158Pm | |
| 62 | 159Sm | |
| 63 | 160Eu | |
| 64 | 161Gd | |
| 65 | 162Tb | |
| 66 | 163Dy | |
| 67 | 164Ho | |
| 68 | 165Er | |
| 69 | 166Tm | 178Tm |
| 70 | 167Yb | 178Yb |
| 71 | 168Lu | 178Lu |
| 72 | 169Hf | 178Hf |
| 73 | 170Ta | 178Ta |
| 74 | 171W | 178W |
| 75 | 172Re | 178Re |
| 76 | 173Os | 178Os |
| 77 | 174Ir | 178Ir |
| 78 | 175Pt | 178Pt |
| 79 | 176Au | 178Au |
| 80 | 177Hg | 178Hg |
| 81 | 178Tl | 178Tl |
| 82 | 179Pb | 178Pb |
External data and identifiers
Last update: 2020-10-22
Perma link: https://www.chemlin.org/isotope/thallium-178
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