Osmium-166

Properties and data of the isotope ¹⁶⁶Os.

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-166; Os-166Symbol:¹⁶⁶Os or 16676OsMass number A:166 (= number of nucleons)Atomic number Z:76 (= number of protons)Neutrons N:90Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.1842105263158 (= neutron-proton ratio)Neutron excess (N-Z):14Isotopic mass:165.972698(19) u (atomic weight of Osmium-166)Nuclide mass:165.9310102 u (calculated nuclear mass without electrons)Mass excess:-25.43165 MeVMass defect:1.401846872 u (per nucleus)Nuclear binding energy:1305.81195019 MeV (per nucleus)
7.86633705 MeV (average binding energy per nucleon)Separation energy:S_N = 11.71(20) MeV (first neutron)
S_P = 2.06(3) MeV (first proton)Half-life:213(5) msDecay constant λ:3.2542121153049 s^-1Specific activity α:1.187716590695 × 10⁺²² Bq g^-1
321004483971.81 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1977

Radioactive Decay

Half-life T_½ = 213(5) ms respectively 2.13 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁶²W	72(13) %	6.143(3) MeV
EC/β⁺	¹⁶⁶Re	28(13) %	6.46(7) MeV

Parent Nuclides

Direct parent isotope is: ¹⁷⁰Pt.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 90) and isobaric (same nucleon number A = 166) with Osmium-166. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 90	Isobar A = 166
50	¹⁴⁰Sn
51	¹⁴¹Sb
52	¹⁴²Te
53	¹⁴³I
54	¹⁴⁴Xe
55	¹⁴⁵Cs
56	¹⁴⁶Ba
57	¹⁴⁷La
58	¹⁴⁸Ce
59	¹⁴⁹Pr
60	¹⁵⁰Nd
61	¹⁵¹Pm
62	¹⁵²Sm	¹⁶⁶Sm
63	¹⁵³Eu	¹⁶⁶Eu
64	¹⁵⁴Gd	¹⁶⁶Gd
65	¹⁵⁵Tb	¹⁶⁶Tb
66	¹⁵⁶Dy	¹⁶⁶Dy
67	¹⁵⁷Ho	¹⁶⁶Ho
68	¹⁵⁸Er	¹⁶⁶Er
69	¹⁵⁹Tm	¹⁶⁶Tm
70	¹⁶⁰Yb	¹⁶⁶Yb
71	¹⁶¹Lu	¹⁶⁶Lu
72	¹⁶²Hf	¹⁶⁶Hf
73	¹⁶³Ta	¹⁶⁶Ta
74	¹⁶⁴W	¹⁶⁶W
75	¹⁶⁵Re	¹⁶⁶Re
76	¹⁶⁶Os	¹⁶⁶Os
77	¹⁶⁷Ir	¹⁶⁶Ir
78	¹⁶⁸Pt	¹⁶⁶Pt
80	¹⁷⁰Hg