Gold-197m

Properties and data of the isotope ¹⁹⁷Au.

Content

General data

Name of the isotope:Gold-197m; Au-197mSymbol:¹⁹⁷Au or 19779AuMass number A:197 (= number of nucleons)Atomic number Z:79 (= number of protons)Neutrons N:118Isotopic mass:196.966568812(707) u (atomic weight of Gold-197m)
Excitation energy: 409.15(8) keVNuclide mass:196.9232357 u (calculated nuclear mass without electrons)Mass excess:-31.14095 MeVMass defect:1.674068804 u (per nucleus)Nuclear binding energy:1559.38504651 MeV (per nucleus)
7.91566013 MeV (average binding energy per nucleon)Half-life:7.73(6) sDecay constant λ:0.089669751689514 s^-1Specific activity α:2.755121814029 × 10⁺²⁰ Bq g^-1
7446275173.053 Ci g^-1Spin and parity:
(nuclear angular momentum)11/2-Magnetic dipole moment:μ(μ_N) = (+) 5.98(9)Quadrupole moment Q:+ 1.68(5) barn (100 fm²)

Radioactive Decay

Half-life T_½ = 7.73(6) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	¹⁹⁷Au	100 %	0.4094 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
¹⁹⁷Au		stable	3/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 118) and isobaric (same nucleon number A = 197) with Gold-197m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 118	Isobar A = 197
72	¹⁹⁰Hf
73	¹⁹¹Ta
74	¹⁹²W	¹⁹⁷W
75	¹⁹³Re	¹⁹⁷Re
76	¹⁹⁴Os	¹⁹⁷Os
77	¹⁹⁵Ir	¹⁹⁷Ir
78	¹⁹⁶Pt	¹⁹⁷Pt
79	¹⁹⁷Au	¹⁹⁷Au
80	¹⁹⁸Hg	¹⁹⁷Hg
81	¹⁹⁹Tl	¹⁹⁷Tl
82	²⁰⁰Pb	¹⁹⁷Pb
83	²⁰¹Bi	¹⁹⁷Bi
84	²⁰²Po	¹⁹⁷Po
85	²⁰³At	¹⁹⁷At
86	²⁰⁴Rn	¹⁹⁷Rn
87	²⁰⁵Fr
88	²⁰⁶Ra
89	²⁰⁷Ac
90	²⁰⁸Th