Gold-186m

Properties and data of the isotope ¹⁸⁶Au.

Content

General data

Name of the isotope:Gold-186m; Au-186mSymbol:¹⁸⁶Au or 18679AuMass number A:186 (= number of nucleons)Atomic number Z:79 (= number of protons)Neutrons N:107Isotopic mass:185.965953(23) u (atomic weight of Gold-186m)
Excitation energy: 227.77(7) keVNuclide mass:185.9226199 u (calculated nuclear mass without electrons)Mass excess:-31.71458 MeVMass defect:1.57937054 u (per nucleus)Nuclear binding energy:1471.17418179 MeV (per nucleus)
7.90953861 MeV (average binding energy per nucleon)Half-life:110(10) nsDecay constant λ:6301338.0050904 s^-1Specific activity α:2.051218652579 × 10⁺²⁸ Bq g^-1
5.543834196161 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)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
¹⁸⁶Au		10.7(5) min	3-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 107) and isobaric (same nucleon number A = 186) with Gold-186m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 107	Isobar A = 186
65	¹⁷²Tb
66	¹⁷³Dy
67	¹⁷⁴Ho
68	¹⁷⁵Er
69	¹⁷⁶Tm
70	¹⁷⁷Yb
71	¹⁷⁸Lu	¹⁸⁶Lu
72	¹⁷⁹Hf	¹⁸⁶Hf
73	¹⁸⁰Ta	¹⁸⁶Ta
74	¹⁸¹W	¹⁸⁶W
75	¹⁸²Re	¹⁸⁶Re
76	¹⁸³Os	¹⁸⁶Os
77	¹⁸⁴Ir	¹⁸⁶Ir
78	¹⁸⁵Pt	¹⁸⁶Pt
79	¹⁸⁶Au	¹⁸⁶Au
80	¹⁸⁷Hg	¹⁸⁶Hg
81	¹⁸⁸Tl	¹⁸⁶Tl
82	¹⁸⁹Pb	¹⁸⁶Pb
83	¹⁹⁰Bi	¹⁸⁶Bi
84	¹⁹¹Po	¹⁸⁶Po
85	¹⁹²At
86	¹⁹³Rn