Iridium-195m

Properties and data of the isotope ^195mIr.

Contents

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

General data

Name of the isotope:Iridium-195m; Ir-195mSymbol:^195mIr or 195m77IrMass number A:195 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:118Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.5324675324675 (= neutron-proton ratio)Neutron excess (N-Z):41Excitation energy:100(5) keVIsotopic mass:194.9659770(14) u (atomic weight of Iridium-195m)Nuclide mass:194.9237408 u (calculated nuclear mass without electrons)Mass excess:-31.69222 MeVMass defect:1.659010552 u (per nucleus)Nuclear binding energy:1545.35837512 MeV (per nucleus)
7.92491474 MeV (average binding energy per nucleon)Half-life:3.67(82) hDecay constant λ:5.246345599151 × 10^-5 s^-1Specific activity α:1.628568670000 × 10⁺¹⁷ Bq g^-1
4401536.9459462 Ci g^-1Spin and parity:
(nuclear angular momentum)11/2-

Radioactive Decay

Half-life T_½ = 3.67(82) h (hours) respectively 1.3212 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁹⁵Pt	95(5) %
Iso	¹⁹⁵Ir	5(5) %

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
¹⁹⁵Ir		2.29(17) h	3/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 118) and isobaric (same nucleon number A = 195) with Iridium-195m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 118	Isobar A = 195
72	¹⁹⁰Hf
73	¹⁹¹Ta
74	¹⁹²W	¹⁹⁵W
75	¹⁹³Re	¹⁹⁵Re
76	¹⁹⁴Os	¹⁹⁵Os
77	¹⁹⁵Ir	¹⁹⁵Ir
78	¹⁹⁶Pt	¹⁹⁵Pt
79	¹⁹⁷Au	¹⁹⁵Au
80	¹⁹⁸Hg	¹⁹⁵Hg
81	¹⁹⁹Tl	¹⁹⁵Tl
82	²⁰⁰Pb	¹⁹⁵Pb
83	²⁰¹Bi	¹⁹⁵Bi
84	²⁰²Po	¹⁹⁵Po
85	²⁰³At	¹⁹⁵At
86	²⁰⁴Rn	¹⁹⁵Rn
87	²⁰⁵Fr
88	²⁰⁶Ra
89	²⁰⁷Ac
90	²⁰⁸Th