See also: List of individual Bismuth isotopes (and general data sources).
General data
Name of the isotope:Bismuth-191m1; Bi-191m1Symbol:191m1Bi or 191m183BiMass number A:191 (= number of nucleons)Atomic number Z:83 (= number of protons)Neutrons N:108Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.3012048192771 (= neutron-proton ratio)Neutron excess (N-Z):25Excitation energy:240(4) keVIsotopic mass:190.985787(8) u (atomic weight of Bismuth-191m1)Nuclide mass:190.9402601 u (calculated nuclear mass without electrons)Mass excess:-13.23932 MeVMass defect:1.599501584 u (per nucleus)Nuclear binding energy:1489.92612849 MeV (per nucleus) 7.80066036 MeV (average binding energy per nucleon)Half-life:125(13) msDecay constant λ:5.5451774444796 s-1Specific activity α:1.748498651883 × 10+22 Bq g-1 472567203211.65 Ci g-1Spin and parity: (nuclear angular momentum)(1/2+)
Radioactive Decay
Half-life T½ = 125(13) ms respectively 1.25 × 10-1 seconds s.
Decay mode
Daughter
Probability
Decay energy
γ energy (intensity)
α
187Tl
68(5) %
EC/β+
191Pb
?
Iso
191Bi
32(5) %
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 = 108) and isobaric (same nucleon number A = 191) with Bismuth-191m1. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
