Osmium-203

Properties and data of the isotope ²⁰³Os.

Contents

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

General data

Name of the isotope:Osmium-203; Os-203Symbol:²⁰³Os or 20376OsMass number A:203 (= number of nucleons)Atomic number Z:76 (= number of protons)Neutrons N:127Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.6710526315789 (= neutron-proton ratio)Neutron excess (N-Z):51Isotopic mass:202.99180(43) u (atomic weight of Osmium-203)Nuclide mass:202.9501122 u (calculated nuclear mass without electrons)Mass excess:-7.63825 MeVMass defect:1.703346764 u (per nucleus)Nuclear binding energy:1586.65729059 MeV (per nucleus)
7.81604577 MeV (average binding energy per nucleon)Separation energy:S_N = 2.62(57) MeV (first neutron)Half-life:Spin and parity:
(nuclear angular momentum)Year of discovery:2012

Radioactive Decay

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²⁰³Ir	?	7.05(57) MeV
β^-, n	²⁰²Ir	?	1.06(50) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 127) and isobaric (same nucleon number A = 203) with Osmium-203. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 127	Isobar A = 203
76	²⁰³Os	²⁰³Os
77	²⁰⁴Ir	²⁰³Ir
78	²⁰⁵Pt	²⁰³Pt
79	²⁰⁶Au	²⁰³Au
80	²⁰⁷Hg	²⁰³Hg
81	²⁰⁸Tl	²⁰³Tl
82	²⁰⁹Pb	²⁰³Pb
83	²¹⁰Bi	²⁰³Bi
84	²¹¹Po	²⁰³Po
85	²¹²At	²⁰³At
86	²¹³Rn	²⁰³Rn
87	²¹⁴Fr	²⁰³Fr
88	²¹⁵Ra	²⁰³Ra
89	²¹⁶Ac	²⁰³Ac
90	²¹⁷Th
91	²¹⁸Pa
92	²¹⁹U
93	²²⁰Np