Gold-203

Properties and data of the isotope ²⁰³Au.

Content

General data

Name of the isotope:Gold-203; Au-203Symbol:²⁰³Au or 20379AuMass number A:203 (= number of nucleons)Atomic number Z:79 (= number of protons)Neutrons N:124Isotopic mass:202.975154(3) u (atomic weight of Gold-203)Nuclide mass:202.9318209 u (calculated nuclear mass without electrons)Mass excess:-23.1439 MeVMass defect:1.717473112 u (per nucleus)Nuclear binding energy:1599.81589899 MeV (per nucleus)
7.8808665 MeV (average binding energy per nucleon)Separation energy:S_N = 6.862(23) MeV (first neutron)
S_P = 7.740(25) MeV (first proton)Half-life:60(6) sDecay constant λ:0.011552453009332 s^-1Specific activity α:3.444084123762 × 10⁺¹⁹ Bq g^-1
930833546.96281 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2+Year of discovery:1952

Radioactive Decay

Half-life T_½ = 60(6) s respectively 6.0 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²⁰³Hg	100 %	2.126(3) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 124) and isobaric (same nucleon number A = 203) with Gold-203. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 124	Isobar A = 203
75	¹⁹⁹Re
76	²⁰⁰Os	²⁰³Os
77	²⁰¹Ir	²⁰³Ir
78	²⁰²Pt	²⁰³Pt
79	²⁰³Au	²⁰³Au
80	²⁰⁴Hg	²⁰³Hg
81	²⁰⁵Tl	²⁰³Tl
82	²⁰⁶Pb	²⁰³Pb
83	²⁰⁷Bi	²⁰³Bi
84	²⁰⁸Po	²⁰³Po
85	²⁰⁹At	²⁰³At
86	²¹⁰Rn	²⁰³Rn
87	²¹¹Fr	²⁰³Fr
88	²¹²Ra	²⁰³Ra
89	²¹³Ac
90	²¹⁴Th
91	²¹⁵Pa
92	²¹⁶U