Lead-204m1

Properties and data of the isotope ^204m1Pb.

Contents

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

General data

Name of the isotope:Lead-204m1; Pb-204m1Symbol:^204m1Pb or 204m182PbMass number A:204 (= number of nucleons)Atomic number Z:82 (= number of protons)Neutrons N:122Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.4878048780488 (= neutron-proton ratio)Neutron excess (N-Z):40Excitation energy:1274.13(5) keVIsotopic mass:203.973044(8) u (atomic weight of Lead-204m1)Nuclide mass:203.9280656 u (calculated nuclear mass without electrons)Mass excess:-25.10935 MeVMass defect:1.725728376 u (per nucleus)Nuclear binding energy:1607.50562787 MeV (per nucleus)
7.87992955 MeV (average binding energy per nucleon)Half-life:265(6) nsDecay constant λ:2615649.7379621 s^-1Specific activity α:7.759512887814 × 10⁺²⁷ Bq g^-1
2.097165645355 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)4+Magnetic dipole moment:μ(μ_N) = +0.224(3)Quadrupole moment Q:0.44(2) barn (100 fm²)Nuclear g-factor:g_l = 0.056

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
^204m2Pb	2185.88(8) keV	66.93(10) min	9-
^204m3Pb	2264.42(6) keV	0.45(+10-3) μs	7-
²⁰⁴Pb		1.4 × 10¹⁷ a	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 122) and isobaric (same nucleon number A = 204) with Lead-204m1. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 122	Isobar A = 204
74	¹⁹⁶W
75	¹⁹⁷Re
76	¹⁹⁸Os
77	¹⁹⁹Ir	²⁰⁴Ir
78	²⁰⁰Pt	²⁰⁴Pt
79	²⁰¹Au	²⁰⁴Au
80	²⁰²Hg	²⁰⁴Hg
81	²⁰³Tl	²⁰⁴Tl
82	²⁰⁴Pb	²⁰⁴Pb
83	²⁰⁵Bi	²⁰⁴Bi
84	²⁰⁶Po	²⁰⁴Po
85	²⁰⁷At	²⁰⁴At
86	²⁰⁸Rn	²⁰⁴Rn
87	²⁰⁹Fr	²⁰⁴Fr
88	²¹⁰Ra	²⁰⁴Ra
89	²¹¹Ac	²⁰⁴Ac
90	²¹²Th
91	²¹³Pa
92	²¹⁴U