Gold-177

Properties and data of the isotope ¹⁷⁷Au.

Content

General data

Name of the isotope:Gold-177; Au-177Symbol:¹⁷⁷Au or 17779AuMass number A:177 (= number of nucleons)Atomic number Z:79 (= number of protons)Neutrons N:98Isotopic mass:176.976870(11) u (atomic weight of Gold-177)Nuclide mass:176.9335369 u (calculated nuclear mass without electrons)Mass excess:-21.54546 MeVMass defect:1.490469296 u (per nucleus)Nuclear binding energy:1388.36320641 MeV (per nucleus)
7.84385992 MeV (average binding energy per nucleon)Separation energy:S_N = 11.10(3) MeV (first neutron)Half-life:1.501(20) sDecay constant λ:0.46179026019983 s^-1Specific activity α:1.580094315153 × 10⁺²¹ Bq g^-1
42705251760.905 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2+Magnetic dipole moment:μ(μ_N) = 1.15(5)Nuclear g-factor:g_l = 2.3Year of discovery:1968

Radioactive Decay

Half-life T_½ = 1.501(20) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁷³Ir	40(6) %	6.298(4) MeV
EE/β⁺	¹⁷⁷Pt	60(6) %	7.825(18) MeV

Parent Nuclides

Direct parent isotope is: ¹⁸¹Tl.

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
^177mAu	182.7(5) keV	1.193(13) s	(11/2-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 98) and isobaric (same nucleon number A = 177) with Gold-177. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 98	Isobar A = 177
57	¹⁵⁵La
58	¹⁵⁶Ce
59	¹⁵⁷Pr
60	¹⁵⁸Nd
61	¹⁵⁹Pm
62	¹⁶⁰Sm
63	¹⁶¹Eu
64	¹⁶²Gd
65	¹⁶³Tb
66	¹⁶⁴Dy
67	¹⁶⁵Ho
68	¹⁶⁶Er	¹⁷⁷Er
69	¹⁶⁷Tm	¹⁷⁷Tm
70	¹⁶⁸Yb	¹⁷⁷Yb
71	¹⁶⁹Lu	¹⁷⁷Lu
72	¹⁷⁰Hf	¹⁷⁷Hf
73	¹⁷¹Ta	¹⁷⁷Ta
74	¹⁷²W	¹⁷⁷W
75	¹⁷³Re	¹⁷⁷Re
76	¹⁷⁴Os	¹⁷⁷Os
77	¹⁷⁵Ir	¹⁷⁷Ir
78	¹⁷⁶Pt	¹⁷⁷Pt
79	¹⁷⁷Au	¹⁷⁷Au
80	¹⁷⁸Hg	¹⁷⁷Hg
81	¹⁷⁹Tl	¹⁷⁷Tl
82	¹⁸⁰Pb