Lead-198

Properties and data of the isotope ¹⁹⁸Pb.

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-198; Pb-198Symbol:¹⁹⁸Pb or 19882PbMass number A:198 (= number of nucleons)Atomic number Z:82 (= number of protons)Neutrons N:116Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.4146341463415 (= neutron-proton ratio)Neutron excess (N-Z):34Isotopic mass:197.972015(9) u (atomic weight of Lead-198)Nuclide mass:197.9270366 u (calculated nuclear mass without electrons)Mass excess:-26.06786 MeVMass defect:1.67476788 u (per nucleus)Nuclear binding energy:1560.03623161 MeV (per nucleus)
7.87897087 MeV (average binding energy per nucleon)Separation energy:S_N = 9.393(10) MeV (first neutron)
S_P = 5.015(19) MeV (first proton)Half-life:2.4(1) hDecay constant λ:8.022536812036 × 10^-5 s^-1Specific activity α:2.452428768330 × 10⁺¹⁷ Bq g^-1
6628185.8603527 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:5.4524(22) femtometer fmYear of discovery:1955

Radioactive Decay

Half-life T_½ = 2.4(1) h (hours) respectively 8.640 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β⁺	¹⁹⁸Tl	100 %	1.461(12) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁹⁸Bi, ²⁰²Po.

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
^198m1Pb	2141.4(4) keV	4.19(10) μs	(7)-
^198m2Pb	2231.4(5) keV	137(10) ns	(9)-
^198m3Pb	2821.7(6) keV	212(4) ns	(12)+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 116) and isobaric (same nucleon number A = 198) with Lead-198. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 116	Isobar A = 198
71	¹⁸⁷Lu
72	¹⁸⁸Hf
73	¹⁸⁹Ta
74	¹⁹⁰W
75	¹⁹¹Re	¹⁹⁸Re
76	¹⁹²Os	¹⁹⁸Os
77	¹⁹³Ir	¹⁹⁸Ir
78	¹⁹⁴Pt	¹⁹⁸Pt
79	¹⁹⁵Au	¹⁹⁸Au
80	¹⁹⁶Hg	¹⁹⁸Hg
81	¹⁹⁷Tl	¹⁹⁸Tl
82	¹⁹⁸Pb	¹⁹⁸Pb
83	¹⁹⁹Bi	¹⁹⁸Bi
84	²⁰⁰Po	¹⁹⁸Po
85	²⁰¹At	¹⁹⁸At
86	²⁰²Rn	¹⁹⁸Rn
87	²⁰³Fr
88	²⁰⁴Ra
89	²⁰⁵Ac