Lead-211

Properties and data of the isotope ²¹¹Pb.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

See also: List of individual Lead isotopes (and general data sources).

General data

Name of the isotope:Lead-211; Pb-211Other names:Actinium BSymbol:²¹¹Pb or 21182PbMass number A:211 (= number of nucleons)Atomic number Z:82 (= number of protons)Neutrons N:129Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.5731707317073 (= neutron-proton ratio)Neutron excess (N-Z):47Isotopic mass:210.9887354(24) u (atomic weight of Lead-211)Nuclide mass:210.943757 u (calculated nuclear mass without electrons)Mass excess:-10.49291 MeVMass defect:1.770691388 u (per nucleus)Nuclear binding energy:1649.38840377 MeV (per nucleus)
7.81700665 MeV (average binding energy per nucleon)Separation energy:S_N = 3.8358(26) MeV (first neutron)
S_P = 8.535(12) MeV (first proton)Half-life:36.1(2) minDecay constant λ:0.00032001254873497 s^-1Specific activity α:9.176955454425 × 10⁺¹⁷ Bq g^-1
24802582.309258 Ci g^-1Spin and parity:
(nuclear angular momentum)9/2+Magnetic dipole moment:μ(μ_N) = - 1.4037(8)Quadrupole moment Q:0.087(62) barn (100 fm²)Nuclear g-factor:g_l = -0.31193333333333Charge radius:5.5290(17) femtometer fmYear of discovery:1904

Radioactive Decay

Half-life T_½ = 36.1(2) min (minutes) respectively 2.166 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²¹¹Bi	100 %	1.366(5) MeV

Parent Nuclides

Direct parent isotopes are: ²¹¹Tl, ²¹⁵Po, ²³⁵U, 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
^211mPb	1679.1+x keV	159(28) ns	(27/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 129) and isobaric (same nucleon number A = 211) with Lead-211. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 129	Isobar A = 211
78	²⁰⁷Pt
79	²⁰⁸Au
80	²⁰⁹Hg	²¹¹Hg
81	²¹⁰Tl	²¹¹Tl
82	²¹¹Pb	²¹¹Pb
83	²¹²Bi	²¹¹Bi
84	²¹³Po	²¹¹Po
85	²¹⁴At	²¹¹At
86	²¹⁵Rn	²¹¹Rn
87	²¹⁶Fr	²¹¹Fr
88	²¹⁷Ra	²¹¹Ra
89	²¹⁸Ac	²¹¹Ac
90	²¹⁹Th	²¹¹Th
91	²²⁰Pa
92	²²¹U
93	²²²Np