Osmium-165

Properties and data of the isotope ¹⁶⁵Os.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Osmium-165; Os-165Symbol:¹⁶⁵Os or 16576OsMass number A:165 (= number of nucleons)Atomic number Z:76 (= number of protons)Neutrons N:89Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.1710526315789 (= neutron-proton ratio)Neutron excess (N-Z):13Isotopic mass:164.97660(21) u (atomic weight of Osmium-165)Nuclide mass:164.9349122 u (calculated nuclear mass without electrons)Mass excess:-21.79696 MeVMass defect:1.389279956 u (per nucleus)Nuclear binding energy:1294.10594333 MeV (per nucleus)
7.84306632 MeV (average binding energy per nucleon)Separation energy:S_N = 9.44(25) MeV (first neutron)
S_P = 1.61(20) MeV (first proton)Half-life:71(3) msDecay constant λ:9.7626363459147 s^-1Specific activity α:3.584876295087 × 10⁺²² Bq g^-1
968885485158.81 Ci g^-1Spin and parity:
(nuclear angular momentum)(7/2-)Year of discovery:1978

Radioactive Decay

Half-life T_½ = 71(3) ms respectively 7.1 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁶¹W	90(2) %	6.335(6) MeV
EC/β⁺	¹⁶⁵Re	10(2) %	8.86(20) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁶⁹Pt, ¹⁶⁶Ir.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 89) and isobaric (same nucleon number A = 165) with Osmium-165. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 89	Isobar A = 165
50	¹³⁹Sn
51	¹⁴⁰Sb
52	¹⁴¹Te
53	¹⁴²I
54	¹⁴³Xe
55	¹⁴⁴Cs
56	¹⁴⁵Ba
57	¹⁴⁶La
58	¹⁴⁷Ce
59	¹⁴⁸Pr
60	¹⁴⁹Nd
61	¹⁵⁰Pm
62	¹⁵¹Sm	¹⁶⁵Sm
63	¹⁵²Eu	¹⁶⁵Eu
64	¹⁵³Gd	¹⁶⁵Gd
65	¹⁵⁴Tb	¹⁶⁵Tb
66	¹⁵⁵Dy	¹⁶⁵Dy
67	¹⁵⁶Ho	¹⁶⁵Ho
68	¹⁵⁷Er	¹⁶⁵Er
69	¹⁵⁸Tm	¹⁶⁵Tm
70	¹⁵⁹Yb	¹⁶⁵Yb
71	¹⁶⁰Lu	¹⁶⁵Lu
72	¹⁶¹Hf	¹⁶⁵Hf
73	¹⁶²Ta	¹⁶⁵Ta
74	¹⁶³W	¹⁶⁵W
75	¹⁶⁴Re	¹⁶⁵Re
76	¹⁶⁵Os	¹⁶⁵Os
77	¹⁶⁶Ir	¹⁶⁵Ir
78	¹⁶⁷Pt	¹⁶⁵Pt