Terbium-149
Properties and data of the isotope 149Tb.
See also: List of individual Terbium isotopes (and general data sources).
General data
Name of the isotope:Terbium-149; Tb-149Symbol:149Tb or 14965TbMass number A:149 (= number of nucleons)Atomic number Z:65 (= number of protons)Neutrons N:84Isotopic mass:148.923254(4) u (atomic weight of Terbium-149)Nuclide mass:148.8875993 u (calculated nuclear mass without electrons)Mass excess:-71.48844 MeVMass defect:1.313226024 u (per nucleus)Nuclear binding energy:1223.262162 MeV (per nucleus)
8.20981317 MeV (average binding energy per nucleon)Separation energy:SN = 9.023(13) MeV (first neutron)
SP = 2.508(3) MeV (first proton)Half-life:4.118(25) hDecay constant λ:4.67559211969 × 10-5 s-1Specific activity α:1.902505023539 × 10+17 Bq g-1
5141905.4690265 Ci g-1Spin and parity:
(nuclear angular momentum)1/2+Magnetic dipole moment:μ(μN) = + 1.35(2)Nuclear g-factor:gl = 2.7Charge radius:4.9427 femtometer fmYear of discovery:1950
Radioactive Decay
Half-life T½ = 4.118(25) h (hours) respectively 1.48248 × 104 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| EC/β+ | 149Gd | 83.3(17) % | 3.638(5) MeV | |
| α | 145Eu | 16.7(17) % | 4.0779(22) MeV | |
Parent Nuclides
Direct parent isotopes are: 149Dy, 153Ho.
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 |
|---|
| 149mTb | 35.78(13) keV | 4.16(4) min | 11/2- |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 84) and isobaric (same nucleon number A = 149) with Terbium-149. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 84 | Isobar A = 149 |
|---|
| 47 | 131Ag | |
| 48 | 132Cd | |
| 49 | 133In | |
| 50 | 134Sn | |
| 51 | 135Sb | |
| 52 | 136Te | |
| 53 | 137I | |
| 54 | 138Xe | |
| 55 | 139Cs | 149Cs |
| 56 | 140Ba | 149Ba |
| 57 | 141La | 149La |
| 58 | 142Ce | 149Ce |
| 59 | 143Pr | 149Pr |
| 60 | 144Nd | 149Nd |
| 61 | 145Pm | 149Pm |
| 62 | 146Sm | 149Sm |
| 63 | 147Eu | 149Eu |
| 64 | 148Gd | 149Gd |
| 65 | 149Tb | 149Tb |
| 66 | 150Dy | 149Dy |
| 67 | 151Ho | 149Ho |
| 68 | 152Er | 149Er |
| 69 | 153Tm | 149Tm |
| 70 | 154Yb | 149Yb |
| 71 | 155Lu | 149Lu |
| 72 | 156Hf | |
| 73 | 157Ta | |
| 74 | 158W | |
| 75 | 159Re | |
| 76 | 160Os | |
External data and identifiers
Last update: 2020-10-08
Perma link: https://www.chemlin.org/isotope/terbium-149
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