Bismuth-206

Properties and data of the isotope ²⁰⁶Bi.

Contents

General data

Name of the isotope:Bismuth-206; Bi-206Symbol:²⁰⁶Bi or 20683BiMass number A:206 (= number of nucleons)Atomic number Z:83 (= number of protons)Neutrons N:123Isotopic mass:205.978499(8) u (atomic weight of Bismuth-206)Nuclide mass:205.9329721 u (calculated nuclear mass without electrons)Mass excess:-20.02805 MeVMass defect:1.736763324 u (per nucleus)Nuclear binding energy:1617.78461573 MeV (per nucleus)
7.85332338 MeV (average binding energy per nucleon)Separation energy:S_N = 7.035(9) MeV (first neutron)
S_P = 3.547(8) MeV (first proton)Half-life:6.243(3) dDecay constant λ:1.285045140483 × 10^-6 s^-1Specific activity α:3.774986754813 × 10⁺¹⁵ Bq g^-1
102026.669049 Ci g^-1Spin and parity:
(nuclear angular momentum)6+Magnetic dipole moment:μ(μ_N) = + 4.361(8)Quadrupole moment Q:-0.39(4) barn (100 fm²)Nuclear g-factor:g_l = 0.72683333333333Charge radius:5.5034(909) femtometer fmYear of discovery:1947

Radioactive Decay

Half-life T_½ = 6.243(3) d respectively 5.393952 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	²⁰⁶Pb	100 %	3.757(8) MeV

Parent Nuclides

Direct parent isotopes are: ²¹⁰At, ²⁰⁶Po.

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
^206mBi	1044.8(7) keV	0.89(1) ms	10-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 123) and isobaric (same nucleon number A = 206) with Bismuth-206. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 123	Isobar A = 206
74	¹⁹⁷W
75	¹⁹⁸Re
76	¹⁹⁹Os
77	²⁰⁰Ir
78	²⁰¹Pt	²⁰⁶Pt
79	²⁰²Au	²⁰⁶Au
80	²⁰³Hg	²⁰⁶Hg
81	²⁰⁴Tl	²⁰⁶Tl
82	²⁰⁵Pb	²⁰⁶Pb
83	²⁰⁶Bi	²⁰⁶Bi
84	²⁰⁷Po	²⁰⁶Po
85	²⁰⁸At	²⁰⁶At
86	²⁰⁹Rn	²⁰⁶Rn
87	²¹⁰Fr	²⁰⁶Fr
88	²¹¹Ra	²⁰⁶Ra
89	²¹²Ac	²⁰⁶Ac
90	²¹³Th
91	²¹⁴Pa
92	²¹⁵U