Osmium-172

Properties and data of the isotope ¹⁷²Os.

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-172; Os-172Symbol:¹⁷²Os or 17276OsMass number A:172 (= number of nucleons)Atomic number Z:76 (= number of protons)Neutrons N:96Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.2631578947368 (= neutron-proton ratio)Neutron excess (N-Z):20Isotopic mass:171.960017(14) u (atomic weight of Osmium-172)Nuclide mass:171.9183292 u (calculated nuclear mass without electrons)Mass excess:-37.24392 MeVMass defect:1.466517368 u (per nucleus)Nuclear binding energy:1366.05212919 MeV (per nucleus)
7.94216354 MeV (average binding energy per nucleon)Separation energy:S_N = 11.013(22) MeV (first neutron)
S_P = 3.28(3) MeV (first proton)Half-life:19.2(9) sDecay constant λ:0.036101415654164 s^-1Specific activity α:1.271390703581 × 10⁺²⁰ Bq g^-1
3436191090.7619 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1971

Radioactive Decay

Half-life T_½ = 19.2(9) s respectively 1.92 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁶⁸W	0.2 %	5.224(7) MeV
EC/β⁺	¹⁷²Re	99.8 %	4.29(4) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁷⁶Pt, ¹⁷²Ir.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 96) and isobaric (same nucleon number A = 172) with Osmium-172. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 96	Isobar A = 172
55	¹⁵¹Cs
56	¹⁵²Ba
57	¹⁵³La
58	¹⁵⁴Ce
59	¹⁵⁵Pr
60	¹⁵⁶Nd
61	¹⁵⁷Pm
62	¹⁵⁸Sm
63	¹⁵⁹Eu
64	¹⁶⁰Gd
65	¹⁶¹Tb	¹⁷²Tb
66	¹⁶²Dy	¹⁷²Dy
67	¹⁶³Ho	¹⁷²Ho
68	¹⁶⁴Er	¹⁷²Er
69	¹⁶⁵Tm	¹⁷²Tm
70	¹⁶⁶Yb	¹⁷²Yb
71	¹⁶⁷Lu	¹⁷²Lu
72	¹⁶⁸Hf	¹⁷²Hf
73	¹⁶⁹Ta	¹⁷²Ta
74	¹⁷⁰W	¹⁷²W
75	¹⁷¹Re	¹⁷²Re
76	¹⁷²Os	¹⁷²Os
77	¹⁷³Ir	¹⁷²Ir
78	¹⁷⁴Pt	¹⁷²Pt
79	¹⁷⁵Au	¹⁷²Au
80	¹⁷⁶Hg	¹⁷²Hg
81	¹⁷⁷Tl
82	¹⁷⁸Pb