Bismuth-197

Properties and data of the isotope ¹⁹⁷Bi.

Contents

General data

Name of the isotope:Bismuth-197; Bi-197Symbol:¹⁹⁷Bi or 19783BiMass number A:197 (= number of nucleons)Atomic number Z:83 (= number of protons)Neutrons N:114Isotopic mass:196.978865(9) u (atomic weight of Bismuth-197)Nuclide mass:196.9333381 u (calculated nuclear mass without electrons)Mass excess:-19.68713 MeVMass defect:1.65841308 u (per nucleus)Nuclear binding energy:1544.80183354 MeV (per nucleus)
7.84163367 MeV (average binding energy per nucleon)Separation energy:S_N = 9.749(26) MeV (first neutron)
S_P = 1.628(11) MeV (first proton)Half-life:9.33(50) minDecay constant λ:0.0012382050385137 s^-1Specific activity α:3.804410793577 × 10⁺¹⁸ Bq g^-1
102821913.33994 Ci g^-1Spin and parity:
(nuclear angular momentum)(9/2-)Year of discovery:1971

Radioactive Decay

Half-life T_½ = 9.33(50) min (minutes) respectively 5.598 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁹³Tl	trace	5.365(11) MeV
EC/β⁺	¹⁹⁷Pb	> 99.999 %	5.058(10) MeV

Parent Nuclides

Direct parent isotopes are: ²⁰¹At, ¹⁹⁷Po.

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
^197mBi	500 keV	5.04(16) min	(1/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 114) and isobaric (same nucleon number A = 197) with Bismuth-197. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 114	Isobar A = 197
70	¹⁸⁴Yb
71	¹⁸⁵Lu
72	¹⁸⁶Hf
73	¹⁸⁷Ta
74	¹⁸⁸W	¹⁹⁷W
75	¹⁸⁹Re	¹⁹⁷Re
76	¹⁹⁰Os	¹⁹⁷Os
77	¹⁹¹Ir	¹⁹⁷Ir
78	¹⁹²Pt	¹⁹⁷Pt
79	¹⁹³Au	¹⁹⁷Au
80	¹⁹⁴Hg	¹⁹⁷Hg
81	¹⁹⁵Tl	¹⁹⁷Tl
82	¹⁹⁶Pb	¹⁹⁷Pb
83	¹⁹⁷Bi	¹⁹⁷Bi
84	¹⁹⁸Po	¹⁹⁷Po
85	¹⁹⁹At	¹⁹⁷At
86	²⁰⁰Rn	¹⁹⁷Rn
87	²⁰¹Fr
88	²⁰²Ra
89	²⁰³Ac