Osmium-184

Properties and data of the isotope ¹⁸⁴Os.

Contents

General data

Name of the isotope:Osmium-184; Os-184Symbol:¹⁸⁴Os or 18476OsMass number A:184 (= number of nucleons)Atomic number Z:76 (= number of protons)Neutrons N:108Isotopic mass:183.952489(9) u (atomic weight of Osmium-184)Nuclide mass:183.9108012 u (calculated nuclear mass without electrons)Mass excess:-44.25621 MeVMass defect:1.57802436 u (per nucleus)Nuclear binding energy:1469.92022319 MeV (per nucleus)
7.98869687 MeV (average binding energy per nucleon)Separation energy:S_N = 8.66(5) MeV (first neutron)
S_P = 5.732(8) MeV (first proton)Half-life:5.6 × 10¹³ aDecay constant λ:3.924920162444 × 10^-22 s^-1Specific activity α:1.2916077640572 Bq g^-1
3.490831794749 × 10^-11 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:5.3823(22) femtometer fmYear of discovery:1937

Radioactive Decay

Half-life T_½ = 5.6 × 10¹³ a respectively 1.766016 × 10²¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁸⁰W	?	2.9587(16) MeV
2 β⁺	¹⁸⁴W	?

Parent Nuclides

Direct parent isotopes are: ¹⁸⁸Pt, ¹⁸⁴Ir.

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 = 108) and isobaric (same nucleon number A = 184) with Osmium-184. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 108	Isobar A = 184
66	¹⁷⁴Dy
67	¹⁷⁵Ho
68	¹⁷⁶Er
69	¹⁷⁷Tm
70	¹⁷⁸Yb	¹⁸⁴Yb
71	¹⁷⁹Lu	¹⁸⁴Lu
72	¹⁸⁰Hf	¹⁸⁴Hf
73	¹⁸¹Ta	¹⁸⁴Ta
74	¹⁸²W	¹⁸⁴W
75	¹⁸³Re	¹⁸⁴Re
76	¹⁸⁴Os	¹⁸⁴Os
77	¹⁸⁵Ir	¹⁸⁴Ir
78	¹⁸⁶Pt	¹⁸⁴Pt
79	¹⁸⁷Au	¹⁸⁴Au
80	¹⁸⁸Hg	¹⁸⁴Hg
81	¹⁸⁹Tl	¹⁸⁴Tl
82	¹⁹⁰Pb	¹⁸⁴Pb
83	¹⁹¹Bi	¹⁸⁴Bi
84	¹⁹²Po
85	¹⁹³At
86	¹⁹⁴Rn