Iridium-165

Properties and data of the isotope ¹⁶⁵Ir.

Contents

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

General data

Name of the isotope:Iridium-165; Ir-165Symbol:¹⁶⁵Ir or 16577IrMass number A:165 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:88Isotopic mass:164.98755(17) u (atomic weight of Iridium-165)Nuclide mass:164.9453138 u (calculated nuclear mass without electrons)Mass excess:-11.5971 MeVMass defect:1.377490072 u (per nucleus)Nuclear binding energy:1283.12373713 MeV (per nucleus)
7.7765075 MeV (average binding energy per nucleon)Separation energy:S_N = 12.32(35) MeV (first neutron)
S_P = -1.54(5) MeV (first proton)Half-life:1 μsDecay constant λ:693147.18055995 s^-1Specific activity α:2.545262169512 × 10⁺²⁷ Bq g^-1
6.879086944627 × 10⁺¹⁶ Ci g^-1Spin and parity:
(nuclear angular momentum)(1/2+)

Radioactive Decay

Half-life T_½ = 1 μs respectively 1 × 10^-6 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁶¹Re	?	6.82(5) MeV
p	¹⁶⁴Os	?

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
^165mIr	180(50) keV	0.30(6) ms	(11/2-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 88) and isobaric (same nucleon number A = 165) with Iridium-165. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 88	Isobar A = 165
49	¹³⁷In
50	¹³⁸Sn
51	¹³⁹Sb
52	¹⁴⁰Te
53	¹⁴¹I
54	¹⁴²Xe
55	¹⁴³Cs
56	¹⁴⁴Ba
57	¹⁴⁵La
58	¹⁴⁶Ce
59	¹⁴⁷Pr
60	¹⁴⁸Nd
61	¹⁴⁹Pm
62	¹⁵⁰Sm	¹⁶⁵Sm
63	¹⁵¹Eu	¹⁶⁵Eu
64	¹⁵²Gd	¹⁶⁵Gd
65	¹⁵³Tb	¹⁶⁵Tb
66	¹⁵⁴Dy	¹⁶⁵Dy
67	¹⁵⁵Ho	¹⁶⁵Ho
68	¹⁵⁶Er	¹⁶⁵Er
69	¹⁵⁷Tm	¹⁶⁵Tm
70	¹⁵⁸Yb	¹⁶⁵Yb
71	¹⁵⁹Lu	¹⁶⁵Lu
72	¹⁶⁰Hf	¹⁶⁵Hf
73	¹⁶¹Ta	¹⁶⁵Ta
74	¹⁶²W	¹⁶⁵W
75	¹⁶³Re	¹⁶⁵Re
76	¹⁶⁴Os	¹⁶⁵Os
77	¹⁶⁵Ir	¹⁶⁵Ir
78	¹⁶⁶Pt