Osmium-161
Properties and data of the isotope 161Os.
See also: List of individual Osmium isotopes (and general data sources).
General data
Name of the isotope:Osmium-161; Os-161Symbol:161Os or 16176OsMass number A:161 (= number of nucleons)Atomic number Z:76 (= number of protons)Neutrons N:85Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.1184210526316 (= neutron-proton ratio)Neutron excess (N-Z):9Isotopic mass:160.98929(43) u (atomic weight of Osmium-161)Nuclide mass:160.9476022 u (calculated nuclear mass without electrons)Mass excess:-9.9763 MeVMass defect:1.341930292 u (per nucleus)Nuclear binding energy:1250.00001542 MeV (per nucleus)
7.76397525 MeV (average binding energy per nucleon)Separation energy:
SP = 0.53(50) MeV (first proton)Half-life:0.64(4) msDecay constant λ:1083.0424696249 s-1Specific activity α:4.076396443359 × 10+24 Bq g-1
1.101728768475 × 10+14 Ci g-1Spin and parity:
(nuclear angular momentum)(7/2-)Year of discovery:2010
Radioactive Decay
Half-life T½ = 0.64(4) ms respectively 6.4 × 10-4 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| α | 157W | ca. 100 % | 7.066(12) MeV | |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 85) and isobaric (same nucleon number A = 161) with Osmium-161. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 85 | Isobar A = 161 |
|---|
| 47 | 132Ag | |
| 48 | 133Cd | |
| 49 | 134In | |
| 50 | 135Sn | |
| 51 | 136Sb | |
| 52 | 137Te | |
| 53 | 138I | |
| 54 | 139Xe | |
| 55 | 140Cs | |
| 56 | 141Ba | |
| 57 | 142La | |
| 58 | 143Ce | |
| 59 | 144Pr | |
| 60 | 145Nd | 161Nd |
| 61 | 146Pm | 161Pm |
| 62 | 147Sm | 161Sm |
| 63 | 148Eu | 161Eu |
| 64 | 149Gd | 161Gd |
| 65 | 150Tb | 161Tb |
| 66 | 151Dy | 161Dy |
| 67 | 152Ho | 161Ho |
| 68 | 153Er | 161Er |
| 69 | 154Tm | 161Tm |
| 70 | 155Yb | 161Yb |
| 71 | 156Lu | 161Lu |
| 72 | 157Hf | 161Hf |
| 73 | 158Ta | 161Ta |
| 74 | 159W | 161W |
| 75 | 160Re | 161Re |
| 76 | 161Os | 161Os |
External data and identifiers
Literature and References
[1] - L. Bianco et al.:
Discovery of 157W and 161Os.
In: Physics Letters B, (2010), DOI 10.1016/j.physletb.2010.04.056.
Last update: 2020-10-21
Perma link: https://www.chemlin.org/isotope/osmium-161
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