Osmium-189m

Properties and data of the isotope ^189mOs.

Contents

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

General data

Name of the isotope:Osmium-189m; Os-189mSymbol:^189mOs or 189m76OsMass number A:189 (= number of nucleons)Atomic number Z:76 (= number of protons)Neutrons N:113Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.4868421052632 (= neutron-proton ratio)Neutron excess (N-Z):37Excitation energy:30.82(2) keVIsotopic mass:188.95814(2) u (atomic weight of Osmium-189m)Nuclide mass:188.9164522 u (calculated nuclear mass without electrons)Mass excess:-38.99234 MeVMass defect:1.61569794 u (per nucleus)Nuclear binding energy:1505.01293692 MeV (per nucleus)
7.96303141 MeV (average binding energy per nucleon)Half-life:5.81(10) hDecay constant λ:3.313956686555 × 10^-5 s^-1Specific activity α:1.061548615434 × 10⁺¹⁷ Bq g^-1
2869050.3119849 Ci g^-1Spin and parity:
(nuclear angular momentum)9/2-

Radioactive Decay

Half-life T_½ = 5.81(10) h (hours) respectively 2.0916 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	¹⁸⁹Os	100 %

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
¹⁸⁹Os		stable	3/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 113) and isobaric (same nucleon number A = 189) with Osmium-189m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 113	Isobar A = 189
70	¹⁸³Yb
71	¹⁸⁴Lu
72	¹⁸⁵Hf	¹⁸⁹Hf
73	¹⁸⁶Ta	¹⁸⁹Ta
74	¹⁸⁷W	¹⁸⁹W
75	¹⁸⁸Re	¹⁸⁹Re
76	¹⁸⁹Os	¹⁸⁹Os
77	¹⁹⁰Ir	¹⁸⁹Ir
78	¹⁹¹Pt	¹⁸⁹Pt
79	¹⁹²Au	¹⁸⁹Au
80	¹⁹³Hg	¹⁸⁹Hg
81	¹⁹⁴Tl	¹⁸⁹Tl
82	¹⁹⁵Pb	¹⁸⁹Pb
83	¹⁹⁶Bi	¹⁸⁹Bi
84	¹⁹⁷Po	¹⁸⁹Po
85	¹⁹⁸At	¹⁸⁹At
86	¹⁹⁹Rn
87	²⁰⁰Fr
88	²⁰¹Ra