Holmium-156
Properties and data of the isotope 156Ho.
See also: List of individual Holmium isotopes (and general data sources).
General data
Name of the isotope:Holmium-156; Ho-156Symbol:156Ho or 15667HoMass number A:156 (= number of nucleons)Atomic number Z:67 (= number of protons)Neutrons N:89Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.3283582089552 (= neutron-proton ratio)Neutron excess (N-Z):22Isotopic mass:155.92971(6) u (atomic weight of Holmium-156)Nuclide mass:155.8929583 u (calculated nuclear mass without electrons)Mass excess:-65.47471 MeVMass defect:1.365744668 u (per nucleus)Nuclear binding energy:1272.18296377 MeV (per nucleus)
8.155019 MeV (average binding energy per nucleon)Separation energy:SN = 7.51(6) MeV (first neutron)
SP = 3.61(6) MeV (first proton)Half-life:56(1) minDecay constant λ:0.00020629380373808 s-1Specific activity α:8.015034481566 × 10+17 Bq g-1
21662255.355586 Ci g-1Spin and parity:
(nuclear angular momentum)4-Magnetic dipole moment:μ(μN) = + 2.98(3)Quadrupole moment Q:+ 2.34(18) barn (100 fm2)Nuclear g-factor:gl = 0.745Charge radius:5.1156(325) femtometer fmYear of discovery:1957
Radioactive Decay
Half-life T½ = 56(1) min (minutes) respectively 3.360 × 103 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| EC/β+ | 156Dy | 100 % | 5.05(6) MeV | |
Parent Nuclides
Direct parent isotope is: 156Er.
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 |
|---|
| 156m1Ho | 52.37 keV | 9.5(15) s | 1- |
| 156m2Ho | 52.37+x keV | 7.6(3) min | 9+ |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 89) and isobaric (same nucleon number A = 156) with Holmium-156. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 89 | Isobar A = 156 |
|---|
| 50 | 139Sn | |
| 51 | 140Sb | |
| 52 | 141Te | |
| 53 | 142I | |
| 54 | 143Xe | |
| 55 | 144Cs | |
| 56 | 145Ba | |
| 57 | 146La | 156La |
| 58 | 147Ce | 156Ce |
| 59 | 148Pr | 156Pr |
| 60 | 149Nd | 156Nd |
| 61 | 150Pm | 156Pm |
| 62 | 151Sm | 156Sm |
| 63 | 152Eu | 156Eu |
| 64 | 153Gd | 156Gd |
| 65 | 154Tb | 156Tb |
| 66 | 155Dy | 156Dy |
| 67 | 156Ho | 156Ho |
| 68 | 157Er | 156Er |
| 69 | 158Tm | 156Tm |
| 70 | 159Yb | 156Yb |
| 71 | 160Lu | 156Lu |
| 72 | 161Hf | 156Hf |
| 73 | 162Ta | 156Ta |
| 74 | 163W | 156W |
| 75 | 164Re | |
| 76 | 165Os | |
| 77 | 166Ir | |
| 78 | 167Pt | |
External data and identifiers
Last update: 2020-10-09
Perma link: https://www.chemlin.org/isotope/holmium-156
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