Lead-210m

Properties and data of the isotope ^210mPb.

Contents

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

General data

Name of the isotope:Lead-210m; Pb-210mSymbol:^210mPb or 210m82PbMass number A:210 (= number of nucleons)Atomic number Z:82 (= number of protons)Neutrons N:128Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.5609756097561 (= neutron-proton ratio)Neutron excess (N-Z):46Excitation energy:1278(5) keVIsotopic mass:209.9841883(16) u (atomic weight of Lead-210m)Nuclide mass:209.9392099 u (calculated nuclear mass without electrons)Mass excess:-14.7285 MeVMass defect:1.766573572 u (per nucleus)Nuclear binding energy:1645.55268288 MeV (per nucleus)
7.83596516 MeV (average binding energy per nucleon)Half-life:201(17) nsDecay constant λ:3448493.4356216 s^-1Specific activity α:9.936513504249 × 10⁺²⁷ Bq g^-1
2.685544190337 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)8+Magnetic dipole moment:μ(μ_N) = -2.496(64)Nuclear g-factor:g_l = -0.312

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
²¹⁰Pb		22.20(22) a	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 128) and isobaric (same nucleon number A = 210) with Lead-210m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 128	Isobar A = 210
77	²⁰⁵Ir
78	²⁰⁶Pt
79	²⁰⁷Au	²¹⁰Au
80	²⁰⁸Hg	²¹⁰Hg
81	²⁰⁹Tl	²¹⁰Tl
82	²¹⁰Pb	²¹⁰Pb
83	²¹¹Bi	²¹⁰Bi
84	²¹²Po	²¹⁰Po
85	²¹³At	²¹⁰At
86	²¹⁴Rn	²¹⁰Rn
87	²¹⁵Fr	²¹⁰Fr
88	²¹⁶Ra	²¹⁰Ra
89	²¹⁷Ac	²¹⁰Ac
90	²¹⁸Th	²¹⁰Th
91	²¹⁹Pa	²¹⁰Pa
92	²²⁰U
93	²²¹Np
95	²²³Am