Lead-202m1

Properties and data of the isotope ^202m1Pb.

Contents

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

General data

Name of the isotope:Lead-202m1; Pb-202m1Symbol:^202m1Pb or 202m182PbMass number A:202 (= number of nucleons)Atomic number Z:82 (= number of protons)Neutrons N:120Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.4634146341463 (= neutron-proton ratio)Neutron excess (N-Z):38Excitation energy:2169.85(8) keVIsotopic mass:201.972152(4) u (atomic weight of Lead-202m1)Nuclide mass:201.9271736 u (calculated nuclear mass without electrons)Mass excess:-25.94024 MeVMass defect:1.709290544 u (per nucleus)Nuclear binding energy:1592.19388599 MeV (per nucleus)
7.88214795 MeV (average binding energy per nucleon)Half-life:3.54(2) hDecay constant λ:5.439008008160 × 10^-5 s^-1Specific activity α:1.629575739475 × 10⁺¹⁷ Bq g^-1
4404258.7553403 Ci g^-1Spin and parity:
(nuclear angular momentum)9-Magnetic dipole moment:μ(μ_N) = - 0.2276(7)Quadrupole moment Q:+0.58(9) barn (100 fm²)Nuclear g-factor:g_l = -0.025288888888889

Radioactive Decay

Half-life T_½ = 3.54(2) h (hours) respectively 1.2744 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	²⁰²Pb	90.5(5) %
EC eu	²⁰²Tl	9.5(5) %

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
²⁰²Pb		52.5(28) × 10³ a	0+
^202m2Pb	4091.0+x keV	110(5) ns	(16+)
^202m3Pb	5251.0+x keV	107(3) ns	(19-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 120) and isobaric (same nucleon number A = 202) with Lead-202m1. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 120	Isobar A = 202
73	¹⁹³Ta
74	¹⁹⁴W
75	¹⁹⁵Re
76	¹⁹⁶Os	²⁰²Os
77	¹⁹⁷Ir	²⁰²Ir
78	¹⁹⁸Pt	²⁰²Pt
79	¹⁹⁹Au	²⁰²Au
80	²⁰⁰Hg	²⁰²Hg
81	²⁰¹Tl	²⁰²Tl
82	²⁰²Pb	²⁰²Pb
83	²⁰³Bi	²⁰²Bi
84	²⁰⁴Po	²⁰²Po
85	²⁰⁵At	²⁰²At
86	²⁰⁶Rn	²⁰²Rn
87	²⁰⁷Fr	²⁰²Fr
88	²⁰⁸Ra	²⁰²Ra
89	²⁰⁹Ac
90	²¹⁰Th