Gold-171m

Properties and data of the isotope ¹⁷¹Au.

Content

General data

Name of the isotope:Gold-171m; Au-171mSymbol:¹⁷¹Au or 17179AuMass number A:171 (= number of nucleons)Atomic number Z:79 (= number of protons)Neutrons N:92Isotopic mass:170.991882(22) u (atomic weight of Gold-171m)
Excitation energy: 259(13) keVNuclide mass:170.9485489 u (calculated nuclear mass without electrons)Mass excess:-7.56187 MeVMass defect:1.4234678 u (per nucleus)Nuclear binding energy:1325.95171489 MeV (per nucleus)
7.7541036 MeV (average binding energy per nucleon)Half-life:1.04(3) msDecay constant λ:666.48767361533 s^-1Specific activity α:2.360989795248 × 10⁺²⁴ Bq g^-1
63810535006727 Ci g^-1Spin and parity:
(nuclear angular momentum)(11/2-)

Radioactive Decay

Half-life T_½ = 1.04(3) ms respectively 1.04 × 10^-3 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁶⁷Ir	60(6) %
p	¹⁷⁰Pt	40(6) %

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
¹⁷¹Au		22 μs	(1/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 92) and isobaric (same nucleon number A = 171) with Gold-171m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 92	Isobar A = 171
53	¹⁴⁵I
54	¹⁴⁶Xe
55	¹⁴⁷Cs
56	¹⁴⁸Ba
57	¹⁴⁹La
58	¹⁵⁰Ce
59	¹⁵¹Pr
60	¹⁵²Nd
61	¹⁵³Pm
62	¹⁵⁴Sm
63	¹⁵⁵Eu
64	¹⁵⁶Gd
65	¹⁵⁷Tb	¹⁷¹Tb
66	¹⁵⁸Dy	¹⁷¹Dy
67	¹⁵⁹Ho	¹⁷¹Ho
68	¹⁶⁰Er	¹⁷¹Er
69	¹⁶¹Tm	¹⁷¹Tm
70	¹⁶²Yb	¹⁷¹Yb
71	¹⁶³Lu	¹⁷¹Lu
72	¹⁶⁴Hf	¹⁷¹Hf
73	¹⁶⁵Ta	¹⁷¹Ta
74	¹⁶⁶W	¹⁷¹W
75	¹⁶⁷Re	¹⁷¹Re
76	¹⁶⁸Os	¹⁷¹Os
77	¹⁶⁹Ir	¹⁷¹Ir
78	¹⁷⁰Pt	¹⁷¹Pt
79	¹⁷¹Au	¹⁷¹Au
80	¹⁷²Hg	¹⁷¹Hg