Bismuth-211

Properties and data of the isotope ²¹¹Bi.

Contents

Bismuth-211 is the radioisotope of the element bismuth, whose atomic nucleus has 128 neutrons in addition to the element-specific 83 protons, resulting in a mass number of 211: ²¹¹Bi.

General data

Name of the isotope:Bismuth-211; Bi-211Other names:Actinium CSymbol:²¹¹Bi or 21183BiMass number A:211 (= number of nucleons)Atomic number Z:83 (= number of protons)Neutrons N:128Isotopic mass:210.987269(6) u (atomic weight of Bismuth-211)Nuclide mass:210.9417421 u (calculated nuclear mass without electrons)Mass excess:-11.85885 MeVMass defect:1.771317904 u (per nucleus)Nuclear binding energy:1649.97199967 MeV (per nucleus)
7.81977251 MeV (average binding energy per nucleon)Separation energy:S_N = 5.139(5) MeV (first neutron)
S_P = 4.420(5) MeV (first proton)Half-life:2.14(2) minDecay constant λ:0.0053983425277254 s^-1Specific activity α:1.548075195816 × 10⁺¹⁹ Bq g^-1
418398701.57205 Ci g^-1Spin and parity:
(nuclear angular momentum)9/2-Magnetic dipole moment:μ(μ_N) = +3.79(7)Nuclear g-factor:g_l = 0.84222222222222Year of discovery:1905

Radioactive Decay

Half-life T_½ = 2.14(2) min (minutes) respectively 1.284 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²¹¹Po	0.276(4) %	0.573(5) MeV
α	²⁰⁷Tl	99.724(4) %	6.7504(5) MeV

Bismuth-211 gamma emissions

E_γ	I_γ	Dose (MeV/Bq-s)
351.07(5) keV	13.02(12) %	0.0457(4)

Parent Nuclides

Direct parent isotopes are: ²¹⁵At, ²¹¹Pb.

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
^211mBi	1257(10) keV	1.4(3) μs	(25/2-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 128) and isobaric (same nucleon number A = 211) with Bismuth-211. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 128	Isobar A = 211
77	²⁰⁵Ir
78	²⁰⁶Pt
79	²⁰⁷Au
80	²⁰⁸Hg	²¹¹Hg
81	²⁰⁹Tl	²¹¹Tl
82	²¹⁰Pb	²¹¹Pb
83	²¹¹Bi	²¹¹Bi
84	²¹²Po	²¹¹Po
85	²¹³At	²¹¹At
86	²¹⁴Rn	²¹¹Rn
87	²¹⁵Fr	²¹¹Fr
88	²¹⁶Ra	²¹¹Ra
89	²¹⁷Ac	²¹¹Ac
90	²¹⁸Th	²¹¹Th
91	²¹⁹Pa
92	²²⁰U
95	²²³Am