Osmium-171

Properties and data of the isotope ¹⁷¹Os.

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-171; Os-171Symbol:¹⁷¹Os or 17176OsMass number A:171 (= number of nucleons)Atomic number Z:76 (= number of protons)Neutrons N:95Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.25 (= neutron-proton ratio)Neutron excess (N-Z):19Isotopic mass:170.963175(19) u (atomic weight of Osmium-171)Nuclide mass:170.9214872 u (calculated nuclear mass without electrons)Mass excess:-34.30227 MeVMass defect:1.454694452 u (per nucleus)Nuclear binding energy:1355.03915387 MeV (per nucleus)
7.92420558 MeV (average binding energy per nucleon)Separation energy:S_N = 8.447(20) MeV (first neutron)
S_P = 2.678(29) MeV (first proton)Half-life:8.3(2) sDecay constant λ:0.083511708501198 s^-1Specific activity α:2.95834865910 × 10⁺²⁰ Bq g^-1
7995536916.5054 Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2-)Year of discovery:1972

Radioactive Decay

Half-life T_½ = 8.3(2) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁶⁷W	1.80(21) %	5.371(4) MeV
EC/β⁺	¹⁷¹Re	98.20(21) %	6.95(3) MeV

Parent Nuclides

Direct parent isotope is: ¹⁷⁵Pt.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 95) and isobaric (same nucleon number A = 171) with Osmium-171. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 95	Isobar A = 171
55	¹⁵⁰Cs
56	¹⁵¹Ba
57	¹⁵²La
58	¹⁵³Ce
59	¹⁵⁴Pr
60	¹⁵⁵Nd
61	¹⁵⁶Pm
62	¹⁵⁷Sm
63	¹⁵⁸Eu
64	¹⁵⁹Gd
65	¹⁶⁰Tb	¹⁷¹Tb
66	¹⁶¹Dy	¹⁷¹Dy
67	¹⁶²Ho	¹⁷¹Ho
68	¹⁶³Er	¹⁷¹Er
69	¹⁶⁴Tm	¹⁷¹Tm
70	¹⁶⁵Yb	¹⁷¹Yb
71	¹⁶⁶Lu	¹⁷¹Lu
72	¹⁶⁷Hf	¹⁷¹Hf
73	¹⁶⁸Ta	¹⁷¹Ta
74	¹⁶⁹W	¹⁷¹W
75	¹⁷⁰Re	¹⁷¹Re
76	¹⁷¹Os	¹⁷¹Os
77	¹⁷²Ir	¹⁷¹Ir
78	¹⁷³Pt	¹⁷¹Pt
79	¹⁷⁴Au	¹⁷¹Au
80	¹⁷⁵Hg	¹⁷¹Hg
81	¹⁷⁶Tl