Bismuth-211m

Properties and data of the isotope ²¹¹Bi.

Content

General data

Name of the isotope:Bismuth-211m; Bi-211mSymbol: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-211m)
Excitation energy: 1257(10) keVNuclide 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)Half-life:1.4(3) μsDecay constant λ:495105.12897139 s^-1Specific activity α:1.419806108163 × 10⁺²⁷ Bq g^-1
3.837313805846 × 10⁺¹⁶ Ci g^-1Spin and parity:
(nuclear angular momentum)(25/2-)

Radioactive Decay

Half-life T_½ = 1.4(3) μs respectively 1.4 × 10^-6 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	²¹¹Bi	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
²¹¹Bi		2.14(2) min	9/2-

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-211m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	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