See also: List of individual Gold isotopes (and general data sources).
General data
Name of the isotope:Gold-197m; Au-197mSymbol:197mAu or 197m79AuMass number A:197 (= number of nucleons)Atomic number Z:79 (= number of protons)Neutrons N:118Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.4936708860759 (= neutron-proton ratio)Neutron excess (N-Z):39Excitation energy:409.15(8) keVIsotopic mass:196.966568812(707) u (atomic weight of Gold-197m)Nuclide mass:196.9232357 u (calculated nuclear mass without electrons)Mass excess:-31.14095 MeVMass defect:1.674068804 u (per nucleus)Nuclear binding energy:1559.38504651 MeV (per nucleus) 7.91566013 MeV (average binding energy per nucleon)Half-life:7.73(6) sDecay constant λ:0.089669751689514 s-1Specific activity α:2.741601632426 × 10+20 Bq g-1 7409734141.6943 Ci g-1Spin and parity: (nuclear angular momentum)11/2-Magnetic dipole moment:μ(μN) = (+) 5.98(9)Quadrupole moment Q:+1.68(5) barn (100 fm2)
Radioactive Decay
Half-life T½ = 7.73(6) s.
Decay mode
Daughter
Probability
Decay energy
γ energy (intensity)
Iso
197Au
100 %
0.4094 MeV
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 = 118) and isobaric (same nucleon number A = 197) with Gold-197m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
