Antimony-129
Properties and data of the isotope 129Sb.
See also: List of individual Antimony isotopes (and general data sources).
General data
Name of the isotope:Antimony-129; Sb-129Symbol:129Sb or 12951SbMass number A:129 (= number of nucleons)Atomic number Z:51 (= number of protons)Neutrons N:78Isotopic mass:128.909147(23) u (atomic weight of Antimony-129)Nuclide mass:128.8811711 u (calculated nuclear mass without electrons)Mass excess:-84.62902 MeVMass defect:1.16579308 u (per nucleus)Nuclear binding energy:1085.92925926 MeV (per nucleus)
8.41805627 MeV (average binding energy per nucleon)Separation energy:SN = 8.070(29) MeV (first neutron)
SP = 8.556(28) MeV (first proton)Half-life:4.366(26) hDecay constant λ:4.410006493102 × 10-5 s-1Specific activity α:2.074818773023 × 10+17 Bq g-1
5607618.3054692 Ci g-1Spin and parity:
(nuclear angular momentum)7/2+Magnetic dipole moment:μ(μN) = 2.79(4)Nuclear g-factor:gl = 0.79714285714286Year of discovery:1939
Radioactive Decay
Half-life T½ = 4.366(26) h (hours) respectively 1.57176 × 104 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| β- | 129Te | 100 % | 2.375(21) MeV | |
Parent Nuclides
Direct parent isotope is: 129Sn.
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 |
|---|
| 129m1Sb | 1851.31(6) keV | 17.7(1) min | (19/2-) |
| 129m2Sb | 1861.06(5) keV | 2.2(2) μs | (15/2-) |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 78) and isobaric (same nucleon number A = 129) with Antimony-129. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 78 | Isobar A = 129 |
|---|
| 43 | 121Tc | |
| 44 | 122Ru | |
| 45 | 123Rh | |
| 46 | 124Pd | 129Pd |
| 47 | 125Ag | 129Ag |
| 48 | 126Cd | 129Cd |
| 49 | 127In | 129In |
| 50 | 128Sn | 129Sn |
| 51 | 129Sb | 129Sb |
| 52 | 130Te | 129Te |
| 53 | 131I | 129I |
| 54 | 132Xe | 129Xe |
| 55 | 133Cs | 129Cs |
| 56 | 134Ba | 129Ba |
| 57 | 135La | 129La |
| 58 | 136Ce | 129Ce |
| 59 | 137Pr | 129Pr |
| 60 | 138Nd | 129Nd |
| 61 | 139Pm | 129Pm |
| 62 | 140Sm | 129Sm |
| 63 | 141Eu | |
| 64 | 142Gd | |
| 65 | 143Tb | |
| 66 | 144Dy | |
| 67 | 145Ho | |
| 68 | 146Er | |
| 69 | 147Tm | |
| 70 | 148Yb | |
| 71 | 149Lu | |
External data and identifiers
Last update: 2020-10-17
Perma link: https://www.chemlin.org/isotope/antimony-129
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