Osmium-178

Properties and data of the isotope ¹⁷⁸Os.

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-178; Os-178Symbol:¹⁷⁸Os or 17876OsMass number A:178 (= number of nucleons)Atomic number Z:76 (= number of protons)Neutrons N:102Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.3421052631579 (= neutron-proton ratio)Neutron excess (N-Z):26Isotopic mass:177.953253(15) u (atomic weight of Osmium-178)Nuclide mass:177.9115652 u (calculated nuclear mass without electrons)Mass excess:-43.54455 MeVMass defect:1.525270864 u (per nucleus)Nuclear binding energy:1420.78065819 MeV (per nucleus)
7.98191381 MeV (average binding energy per nucleon)Separation energy:S_N = 9.659(20) MeV (first neutron)
S_P = 4.56(3) MeV (first proton)Half-life:5.0(4) minDecay constant λ:0.0023104906018665 s^-1Specific activity α:7.861073367231 × 10⁺¹⁸ Bq g^-1
212461442.35761 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1967

Radioactive Decay

Half-life T_½ = 5.0(4) min (minutes) respectively 3.00 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁷⁸Re	ca. 100 %	2.11(3) MeV
α	¹⁷⁴W	≥ 0 %	4.26(3) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁸²Pt, ¹⁷⁸Ir.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 102) and isobaric (same nucleon number A = 178) with Osmium-178. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 102	Isobar A = 178
60	¹⁶²Nd
61	¹⁶³Pm
62	¹⁶⁴Sm
63	¹⁶⁵Eu
64	¹⁶⁶Gd
65	¹⁶⁷Tb
66	¹⁶⁸Dy
67	¹⁶⁹Ho
68	¹⁷⁰Er
69	¹⁷¹Tm	¹⁷⁸Tm
70	¹⁷²Yb	¹⁷⁸Yb
71	¹⁷³Lu	¹⁷⁸Lu
72	¹⁷⁴Hf	¹⁷⁸Hf
73	¹⁷⁵Ta	¹⁷⁸Ta
74	¹⁷⁶W	¹⁷⁸W
75	¹⁷⁷Re	¹⁷⁸Re
76	¹⁷⁸Os	¹⁷⁸Os
77	¹⁷⁹Ir	¹⁷⁸Ir
78	¹⁸⁰Pt	¹⁷⁸Pt
79	¹⁸¹Au	¹⁷⁸Au
80	¹⁸²Hg	¹⁷⁸Hg
81	¹⁸³Tl	¹⁷⁸Tl
82	¹⁸⁴Pb	¹⁷⁸Pb
83	¹⁸⁵Bi
84	¹⁸⁶Po