Lead-203m2

Properties and data of the isotope ^203m2Pb.

Contents

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

General data

Name of the isotope:Lead-203m2; Pb-203m2Symbol:^203m2Pb or 203m282PbMass number A:203 (= number of nucleons)Atomic number Z:82 (= number of protons)Neutrons N:121Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.4756097560976 (= neutron-proton ratio)Neutron excess (N-Z):39Excitation energy:2923.4+x keVIsotopic mass:202.973391(7) u (atomic weight of Lead-203m2)Nuclide mass:202.9284126 u (calculated nuclear mass without electrons)Mass excess:-24.78612 MeVMass defect:1.71671646 u (per nucleus)Nuclear binding energy:1599.11108219 MeV (per nucleus)
7.87739449 MeV (average binding energy per nucleon)Half-life:122(4) nsDecay constant λ:5681534.2668848 s^-1Specific activity α:1.693811864145 × 10⁺²⁸ Bq g^-1
4.577869903095 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)(25/2-)

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
²⁰³Pb		51.92(3) h	5/2-
^203m1Pb	825.2(3) keV	6.21(11) s	13/2+
^203m3Pb	2949.2(4) keV	480(7) ms	29/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 121) and isobaric (same nucleon number A = 203) with Lead-203m2. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 121	Isobar A = 203
73	¹⁹⁴Ta
74	¹⁹⁵W
75	¹⁹⁶Re
76	¹⁹⁷Os	²⁰³Os
77	¹⁹⁸Ir	²⁰³Ir
78	¹⁹⁹Pt	²⁰³Pt
79	²⁰⁰Au	²⁰³Au
80	²⁰¹Hg	²⁰³Hg
81	²⁰²Tl	²⁰³Tl
82	²⁰³Pb	²⁰³Pb
83	²⁰⁴Bi	²⁰³Bi
84	²⁰⁵Po	²⁰³Po
85	²⁰⁶At	²⁰³At
86	²⁰⁷Rn	²⁰³Rn
87	²⁰⁸Fr	²⁰³Fr
88	²⁰⁹Ra	²⁰³Ra
89	²¹⁰Ac	²⁰³Ac
90	²¹¹Th
91	²¹²Pa