See also: List of individual Holmium isotopes (and general data sources).
General data
Name of the isotope:Holmium-166m; Ho-166mSymbol:166mHo or 166m67HoMass number A:166 (= number of nucleons)Atomic number Z:67 (= number of protons)Neutrons N:99Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.4776119402985 (= neutron-proton ratio)Neutron excess (N-Z):32Excitation energy:5.969(12) keVIsotopic mass:165.9322901(11) u (atomic weight of Holmium-166m)Nuclide mass:165.8955384 u (calculated nuclear mass without electrons)Mass excess:-63.07137 MeVMass defect:1.449813728 u (per nucleus)Nuclear binding energy:1350.49278875 MeV (per nucleus) 8.13549873 MeV (average binding energy per nucleon)Half-life:1200(180) yearsDecay constant λ:1.831639089289 × 10-11 s-1Specific activity α:66475237644.065 Bq g-1 1.7966280444342 Ci g-1Spin and parity: (nuclear angular momentum)7-Magnetic dipole moment:μ(μN) = 3.60(5)Quadrupole moment Q:- 0.03(3) barn (100 fm2)Nuclear g-factor:gl = 0.51428571428571
Radioactive Decay
Half-life T½ = 1200(180) years respectively 3.7843 × 1010 seconds s.
Decay mode
Daughter
Probability
Decay energy
γ energy (intensity)
β-
166Er
100 %
Nuclear Isomers
Nuclear isomers or excited states with the activation energy in keV related to the ground state.
The following table shows the atomic nuclei that are isotonic (same neutron number N = 99) and isobaric (same nucleon number A = 166) with Holmium-166m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
