Gold-201

Properties and data of the isotope ²⁰¹Au.

Content

General data

Name of the isotope:Gold-201; Au-201Symbol:²⁰¹Au or 20179AuMass number A:201 (= number of nucleons)Atomic number Z:79 (= number of protons)Neutrons N:122Isotopic mass:200.971658(3) u (atomic weight of Gold-201)Nuclide mass:200.9283249 u (calculated nuclear mass without electrons)Mass excess:-26.4004 MeVMass defect:1.70363928 u (per nucleus)Nuclear binding energy:1586.92976748 MeV (per nucleus)
7.89517297 MeV (average binding energy per nucleon)Separation energy:S_N = 7.232(27) MeV (first neutron)
S_P = 7.090(20) MeV (first proton)Half-life:26.0(8) minDecay constant λ:0.00044432511574355 s^-1Specific activity α:1.337894217307 × 10⁺¹⁸ Bq g^-1
36159303.170478 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2+Year of discovery:1952

Radioactive Decay

Half-life T_½ = 26.0(8) min (minutes) respectively 1.560 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²⁰¹Hg	100 %	1.262(3) MeV

Parent Nuclides

Direct parent isotope is: ²⁰¹Pt.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 122) and isobaric (same nucleon number A = 201) with Gold-201. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 122	Isobar A = 201
74	¹⁹⁶W
75	¹⁹⁷Re
76	¹⁹⁸Os	²⁰¹Os
77	¹⁹⁹Ir	²⁰¹Ir
78	²⁰⁰Pt	²⁰¹Pt
79	²⁰¹Au	²⁰¹Au
80	²⁰²Hg	²⁰¹Hg
81	²⁰³Tl	²⁰¹Tl
82	²⁰⁴Pb	²⁰¹Pb
83	²⁰⁵Bi	²⁰¹Bi
84	²⁰⁶Po	²⁰¹Po
85	²⁰⁷At	²⁰¹At
86	²⁰⁸Rn	²⁰¹Rn
87	²⁰⁹Fr	²⁰¹Fr
88	²¹⁰Ra	²⁰¹Ra
89	²¹¹Ac
90	²¹²Th
91	²¹³Pa
92	²¹⁴U