Gold-198m2

Properties and data of the isotope ^198m2Au.

Contents

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

General data

Name of the isotope:Gold-198m2; Gold-198m2Symbol:^198m2Au or 198m279AuMass number A:198 (= number of nucleons)Atomic number Z:79 (= number of protons)Neutrons N:119Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.5063291139241 (= neutron-proton ratio)Neutron excess (N-Z):40Excitation energy:811.7(15) keVIsotopic mass:197.9682437(6) u (atomic weight of Gold-198m2)Nuclide mass:197.9249106 u (calculated nuclear mass without electrons)Mass excess:-29.5808 MeVMass defect:1.681058832 u (per nucleus)Nuclear binding energy:1565.89621566 MeV (per nucleus)
7.90856675 MeV (average binding energy per nucleon)Half-life:2.272(16) dDecay constant λ:3.531046132058 × 10^-6 s^-1Specific activity α:1.07941407056 × 10⁺¹⁶ Bq g^-1
291733.53258595 Ci g^-1Spin and parity:
(nuclear angular momentum)(12-)Magnetic dipole moment:μ(μ_N) = (+) 5.85(9)

Radioactive Decay

Half-life T_½ = 2.272(16) d respectively 1.963008 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	¹⁹⁸Au	100 %	0.8119(15) MeV

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
¹⁹⁸Au		2.6941(2) d	2-
^198m1Au	312.2227(20) keV	124(4) ns	5+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 119) and isobaric (same nucleon number A = 198) with Gold-198m2. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 119	Isobar A = 198
73	¹⁹²Ta
74	¹⁹³W
75	¹⁹⁴Re	¹⁹⁸Re
76	¹⁹⁵Os	¹⁹⁸Os
77	¹⁹⁶Ir	¹⁹⁸Ir
78	¹⁹⁷Pt	¹⁹⁸Pt
79	¹⁹⁸Au	¹⁹⁸Au
80	¹⁹⁹Hg	¹⁹⁸Hg
81	²⁰⁰Tl	¹⁹⁸Tl
82	²⁰¹Pb	¹⁹⁸Pb
83	²⁰²Bi	¹⁹⁸Bi
84	²⁰³Po	¹⁹⁸Po
85	²⁰⁴At	¹⁹⁸At
86	²⁰⁵Rn	¹⁹⁸Rn
87	²⁰⁶Fr
88	²⁰⁷Ra
89	²⁰⁸Ac
90	²⁰⁹Th
91	²¹⁰Pa