Gold-202

Properties and data of the isotope ²⁰²Au.

Content

General data

Name of the isotope:Gold-202; Au-202Symbol:²⁰²Au or 20279AuMass number A:202 (= number of nucleons)Atomic number Z:79 (= number of protons)Neutrons N:123Isotopic mass:201.973856(25) u (atomic weight of Gold-202)Nuclide mass:201.9305229 u (calculated nuclear mass without electrons)Mass excess:-24.35298 MeVMass defect:1.710106196 u (per nucleus)Nuclear binding energy:1592.95366094 MeV (per nucleus)
7.88590921 MeV (average binding energy per nucleon)Separation energy:S_N = 6.024(24) MeV (first neutron)
S_P = 7.90(6) MeV (first proton)Half-life:28.4(12) sDecay constant λ:0.024406590864787 s^-1Specific activity α:7.312434233760 × 10⁺¹⁹ Bq g^-1
1976333576.6921 Ci g^-1Spin and parity:
(nuclear angular momentum)(1-)Year of discovery:1967

Radioactive Decay

Half-life T_½ = 28.4(12) s respectively 2.84 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²⁰²Hg	100 %	2.992(23) MeV

Parent Nuclides

Direct parent isotope is: ²⁰²Pt.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 123) and isobaric (same nucleon number A = 202) with Gold-202. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 123	Isobar A = 202
74	¹⁹⁷W
75	¹⁹⁸Re
76	¹⁹⁹Os	²⁰²Os
77	²⁰⁰Ir	²⁰²Ir
78	²⁰¹Pt	²⁰²Pt
79	²⁰²Au	²⁰²Au
80	²⁰³Hg	²⁰²Hg
81	²⁰⁴Tl	²⁰²Tl
82	²⁰⁵Pb	²⁰²Pb
83	²⁰⁶Bi	²⁰²Bi
84	²⁰⁷Po	²⁰²Po
85	²⁰⁸At	²⁰²At
86	²⁰⁹Rn	²⁰²Rn
87	²¹⁰Fr	²⁰²Fr
88	²¹¹Ra	²⁰²Ra
89	²¹²Ac
90	²¹³Th
91	²¹⁴Pa
92	²¹⁵U