Terbium-158
Properties and data of the isotope 158Tb.
See also: List of individual Terbium isotopes (and general data sources).
General data
Name of the isotope:Terbium-158; Tb-158Symbol:158Tb or 15865TbMass number A:158 (= number of nucleons)Atomic number Z:65 (= number of protons)Neutrons N:93Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.4307692307692 (= neutron-proton ratio)Neutron excess (N-Z):28Isotopic mass:157.9254202(15) u (atomic weight of Terbium-158)Nuclide mass:157.8897655 u (calculated nuclear mass without electrons)Mass excess:-69.47064 MeVMass defect:1.389044068 u (per nucleus)Nuclear binding energy:1293.88621508 MeV (per nucleus)
8.18915326 MeV (average binding energy per nucleon)Separation energy:SN = 6.7785(10) MeV (first neutron)
SP = 5.9362(10) MeV (first proton)Half-life:180(11) aDecay constant λ:1.221189535870 × 10-10 s-1Specific activity α:468418815394.35 Bq g-1
12.659967983631 Ci g-1Spin and parity:
(nuclear angular momentum)3-Magnetic dipole moment:μ(μN) = + 1.758(7)Quadrupole moment Q:+ 2.7(5) barn (100 fm2)Nuclear g-factor:gl = 0.586Year of discovery:1957
Radioactive Decay
Half-life T½ = 180(11) a respectively 5.676 × 109 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| EC/β+ | 158Gd | 83.4(7) % | 1.2189(18) MeV | |
| β- | 158Dy | 16.6(7) % | 0.9367(25) MeV | |
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 |
|---|
| 158m1Tb | 110.3(12) keV | 10.70(17) s | 0- |
| 158m2Tb | 388.39(11) keV | 0.40(4) ms | 7- |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 93) and isobaric (same nucleon number A = 158) with Terbium-158. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 93 | Isobar A = 158 |
|---|
| 54 | 147Xe | |
| 55 | 148Cs | |
| 56 | 149Ba | |
| 57 | 150La | |
| 58 | 151Ce | 158Ce |
| 59 | 152Pr | 158Pr |
| 60 | 153Nd | 158Nd |
| 61 | 154Pm | 158Pm |
| 62 | 155Sm | 158Sm |
| 63 | 156Eu | 158Eu |
| 64 | 157Gd | 158Gd |
| 65 | 158Tb | 158Tb |
| 66 | 159Dy | 158Dy |
| 67 | 160Ho | 158Ho |
| 68 | 161Er | 158Er |
| 69 | 162Tm | 158Tm |
| 70 | 163Yb | 158Yb |
| 71 | 164Lu | 158Lu |
| 72 | 165Hf | 158Hf |
| 73 | 166Ta | 158Ta |
| 74 | 167W | 158W |
| 75 | 168Re | |
| 76 | 169Os | |
| 77 | 170Ir | |
| 78 | 171Pt | |
| 79 | 172Au | |
| 80 | 173Hg | |
External data and identifiers
Last update: 2020-10-08
Perma link: https://www.chemlin.org/isotope/terbium-158
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