Bismuth-191m2

Properties and data of the isotope ^191m2Bi.

Contents

General data

Name of the isotope:Bismuth-191m2; Bi-191m2Symbol:^191m2Bi or 191m283BiMass number A:191 (= number of nucleons)Atomic number Z:83 (= number of protons)Neutrons N:108Isotopic mass:190.985787(8) u (atomic weight of Bismuth-191m2)
Excitation energy: 429.7(4) keVNuclide 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:562(10) nsDecay constant λ:1233357.9725266 s^-1Specific activity α:3.909187074358 × 10⁺²⁷ Bq g^-1
1.056537047123 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)(13/2+)

Radioactive Decay

Half-life T_½ = 562(10) ns respectively 5.62 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	¹¹⁹¹Bi	100 %

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
¹⁹¹Bi		12.4(3) s	(9/2-)
^191m1Bi	240(4) keV	125(13) ms	(1/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 108) and isobaric (same nucleon number A = 191) with Bismuth-191m2. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 108	Isobar A = 191
66	¹⁷⁴Dy
67	¹⁷⁵Ho
68	¹⁷⁶Er
69	¹⁷⁷Tm
70	¹⁷⁸Yb
71	¹⁷⁹Lu
72	¹⁸⁰Hf
73	¹⁸¹Ta	¹⁹¹Ta
74	¹⁸²W	¹⁹¹W
75	¹⁸³Re	¹⁹¹Re
76	¹⁸⁴Os	¹⁹¹Os
77	¹⁸⁵Ir	¹⁹¹Ir
78	¹⁸⁶Pt	¹⁹¹Pt
79	¹⁸⁷Au	¹⁹¹Au
80	¹⁸⁸Hg	¹⁹¹Hg
81	¹⁸⁹Tl	¹⁹¹Tl
82	¹⁹⁰Pb	¹⁹¹Pb
83	¹⁹¹Bi	¹⁹¹Bi
84	¹⁹²Po	¹⁹¹Po
85	¹⁹³At	¹⁹¹At
86	¹⁹⁴Rn