Iridium-192

Properties and data of the isotope ¹⁹²Ir.

Contents

See also: List of individual Iridium isotopes (and general data sources).

General data

Name of the isotope:Iridium-192; Ir-192Symbol:¹⁹²Ir or 19277IrMass number A:192 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:115Isotopic mass:191.9626025(14) u (atomic weight of Iridium-192)Nuclide mass:191.9203663 u (calculated nuclear mass without electrons)Mass excess:-34.83555 MeVMass defect:1.636390304 u (per nucleus)Nuclear binding energy:1524.28774983 MeV (per nucleus)
7.9389987 MeV (average binding energy per nucleon)Separation energy:S_N = 9.19812(11) MeV (first neutron)
S_P = 5.7293(11) MeV (first proton)Half-life:73.829(11) dDecay constant λ:1.086637610158 × 10^-7 s^-1Specific activity α:3.426117671244 × 10⁺¹⁴ Bq g^-1
9259.7774898503 Ci g^-1Spin and parity:
(nuclear angular momentum)4+Magnetic dipole moment:μ(μ_N) = +1.924(10)Quadrupole moment Q:+2.22(7) barn (100 fm²)Nuclear g-factor:g_l = 0.481Year of discovery:1937

Radioactive Decay

Half-life T_½ = 73.829(11) d respectively 6.3788256 × 10⁶ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁹²Pt	95.24(4) %	1.4529(23) MeV
EC	¹⁹²Os	4.76(4) %	1.0466(27) MeV

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
^192m1Ir	56.720(5) keV	1.45(5) min	1-
^192m2Ir	168.14(12) keV	241(9) a	(11-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 115) and isobaric (same nucleon number A = 192) with Iridium-192. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 115	Isobar A = 192
70	¹⁸⁵Yb
71	¹⁸⁶Lu
72	¹⁸⁷Hf
73	¹⁸⁸Ta	¹⁹²Ta
74	¹⁸⁹W	¹⁹²W
75	¹⁹⁰Re	¹⁹²Re
76	¹⁹¹Os	¹⁹²Os
77	¹⁹²Ir	¹⁹²Ir
78	¹⁹³Pt	¹⁹²Pt
79	¹⁹⁴Au	¹⁹²Au
80	¹⁹⁵Hg	¹⁹²Hg
81	¹⁹⁶Tl	¹⁹²Tl
82	¹⁹⁷Pb	¹⁹²Pb
83	¹⁹⁸Bi	¹⁹²Bi
84	¹⁹⁹Po	¹⁹²Po
85	²⁰⁰At	¹⁹²At
86	²⁰¹Rn
87	²⁰²Fr
88	²⁰³Ra
89	²⁰⁴Ac