Osmium-188

Properties and data of the isotope ¹⁸⁸Os.

Contents

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

General data

Name of the isotope:Osmium-188; Os-188Symbol:¹⁸⁸Os or 18876OsMass number A:188 (= number of nucleons)Atomic number Z:76 (= number of protons)Neutrons N:112Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.4736842105263 (= neutron-proton ratio)Neutron excess (N-Z):36Isotopic mass:187.95584(1) u (atomic weight of Osmium-188)Nuclide mass:187.9141522 u (calculated nuclear mass without electrons)Mass excess:-41.13478 MeVMass defect:1.609333024 u (per nucleus)Nuclear binding energy:1499.08405586 MeV (per nucleus)
7.97385136 MeV (average binding energy per nucleon)Separation energy:S_N = 7.98961(15) MeV (first neutron)
S_P = 7.20973(15) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)0+Charge radius:5.3993(11) femtometer fmYear of discovery:1931

Parent Nuclides

Direct parent isotopes are: ¹⁸⁸Ir, ¹⁸⁸Re.

Occurrence

Comparison of the natural Osmium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Osmium Isotopic mixture	190.23 u	100 %
Isotope ¹⁸⁴Os	183.952489(9) u	0.02(1) %	5.6 × 10¹³ a	0+
Isotope ¹⁸⁶Os	185.95384(1) u	1.59(3) %	2.0(11) × 10¹⁵ a	0+
Isotope ¹⁸⁷Os	186.95575(1) u	1.96(2) %	stable	1/2-
Isotope ¹⁸⁸Os	187.95584(1) u	13.24(8) %	stable	0+
Isotope ¹⁸⁹Os	188.95814(2) u	16.15(5) %	stable	3/2-
Isotope ¹⁹⁰Os	189.95844(2) u	26.26(2) %	stable	0+
Isotope ¹⁹²Os	191.96148(2) u	40.78(19) %	stable	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 112) and isobaric (same nucleon number A = 188) with Osmium-188. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 112	Isobar A = 188
70	¹⁸²Yb
71	¹⁸³Lu	¹⁸⁸Lu
72	¹⁸⁴Hf	¹⁸⁸Hf
73	¹⁸⁵Ta	¹⁸⁸Ta
74	¹⁸⁶W	¹⁸⁸W
75	¹⁸⁷Re	¹⁸⁸Re
76	¹⁸⁸Os	¹⁸⁸Os
77	¹⁸⁹Ir	¹⁸⁸Ir
78	¹⁹⁰Pt	¹⁸⁸Pt
79	¹⁹¹Au	¹⁸⁸Au
80	¹⁹²Hg	¹⁸⁸Hg
81	¹⁹³Tl	¹⁸⁸Tl
82	¹⁹⁴Pb	¹⁸⁸Pb
83	¹⁹⁵Bi	¹⁸⁸Bi
84	¹⁹⁶Po	¹⁸⁸Po
85	¹⁹⁷At	¹⁸⁸At
86	¹⁹⁸Rn
87	¹⁹⁹Fr