See also: List of individual Thulium isotopes (and general data sources).
General data
Name of the isotope:Thulium-164m; Tm-164mSymbol:164mTm or 164m69TmMass number A:164 (= number of nucleons)Atomic number Z:69 (= number of protons)Neutrons N:95Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.3768115942029 (= neutron-proton ratio)Neutron excess (N-Z):26Excitation energy:+x keVIsotopic mass:163.933543(26) u (atomic weight of Thulium-164m)Nuclide mass:163.8956944 u (calculated nuclear mass without electrons)Mass excess:-61.9043 MeVMass defect:1.429551228 u (per nucleus)Nuclear binding energy:1331.61839157 MeV (per nucleus) 8.11962434 MeV (average binding energy per nucleon)Half-life:5.1(1) minDecay constant λ:0.002265186864575 s-1Specific activity α:8.32122206141 × 10+18 Bq g-1 224897893.55173 Ci g-1Spin and parity: (nuclear angular momentum)6-
Radioactive Decay
Half-life T½ = 5.1(1) min (minutes) respectively 3.06 × 102 seconds s.
Decay mode
Daughter
Probability
Decay energy
γ energy (intensity)
EC/β+
164Er
ca. 20 %
Iso
164Tm
ca. 80 %
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 = 95) and isobaric (same nucleon number A = 164) with Thulium-164m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
