Gold-184m

Properties and data of the isotope ¹⁸⁴Au.

Content

General data

Name of the isotope:Gold-184m; Au-184mSymbol:¹⁸⁴Au or 18479AuMass number A:184 (= number of nucleons)Atomic number Z:79 (= number of protons)Neutrons N:105Isotopic mass:183.967452(24) u (atomic weight of Gold-184m)
Excitation energy: 66.46(4) keVNuclide mass:183.9241189 u (calculated nuclear mass without electrons)Mass excess:-30.31827 MeVMass defect:1.560541708 u (per nucleus)Nuclear binding energy:1453.63523775 MeV (per nucleus)
7.90019151 MeV (average binding energy per nucleon)Half-life:47.6(14) sDecay constant λ:0.014561915557982 s^-1Specific activity α:4.792016758506 × 10⁺¹⁹ Bq g^-1
1295139664.4613 Ci g^-1Spin and parity:
(nuclear angular momentum)2+Magnetic dipole moment:μ(μ_N) = + 1.44(2)Quadrupole moment Q:+ 1.90(16) barn (100 fm²)Nuclear g-factor:g_l = 0.72

Radioactive Decay

Half-life T_½ = 47.6(14) s respectively 4.76 × 10¹ seconds s.

Decay mode	Daughter	Probability
α	¹⁸⁰Ir	≤ 0.016 %
EE/β⁺	¹⁸⁴Pt	70(10) %
Iso	¹⁸⁴Au	30(10) %

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
¹⁸⁴Au		20.6(9) s	5+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 105) and isobaric (same nucleon number A = 184) with Gold-184m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 105	Isobar A = 184
63	¹⁶⁸Eu
64	¹⁶⁹Gd
65	¹⁷⁰Tb
66	¹⁷¹Dy
67	¹⁷²Ho
68	¹⁷³Er
69	¹⁷⁴Tm
70	¹⁷⁵Yb	¹⁸⁴Yb
71	¹⁷⁶Lu	¹⁸⁴Lu
72	¹⁷⁷Hf	¹⁸⁴Hf
73	¹⁷⁸Ta	¹⁸⁴Ta
74	¹⁷⁹W	¹⁸⁴W
75	¹⁸⁰Re	¹⁸⁴Re
76	¹⁸¹Os	¹⁸⁴Os
77	¹⁸²Ir	¹⁸⁴Ir
78	¹⁸³Pt	¹⁸⁴Pt
79	¹⁸⁴Au	¹⁸⁴Au
80	¹⁸⁵Hg	¹⁸⁴Hg
81	¹⁸⁶Tl	¹⁸⁴Tl
82	¹⁸⁷Pb	¹⁸⁴Pb
83	¹⁸⁸Bi	¹⁸⁴Bi
84	¹⁸⁹Po
85	¹⁹⁰At