Osmium-187 (¹⁸⁷Os)

Data nuklida

Unsur

Osmium (Os, Z = 76)

Nomor massa (A)

187

Proton (Z)

76

Neutron (N)

111

Massa atom

186.955749569 ± 0.000000791 u

Waktu paruh

Stable >3.2Py

Mode peluruhan

Peluruhan alfa (α)

Inti anak

Wolfram-183 (¹⁸³W)

Kelimpahan alami

0.0196(17)

Tahun penemuan

1931

Sumber data

IAEA Atomic Mass Data Center (NUBASE) and IUPAC CIAAW, via PubChem

Kegunaan isotop osmium

• The isotope-amount ratio n(187Os)/n(186Os) in rocks can be transferred to fluids, such as magmas, groundwaters, rivers, and oceans. Variations in the inherited n(187Os)/n(186Os) ratios can provide a useful tracer for fluid sources and migration paths, including different layers of the Earth,,,. Meteorites and meteorite dust impacting the Earth have different osmium isotopic compositions than terrestrial rocks and sediments. As a result, n(187Os)/n(186Os)-ratio studies provide evidence of continuing extraterrestrial additions to the Earth over geologic time, as well as providing a method for prospecting in the sedimentary record for large meteorite impact events that may have affected life on Earth.
• Some 187Os is radiogenic as a result of being formed by the beta decay of radioactive 187Re, which has a half-life of 4.16×1010 years. Variations in the isotope-amount ratio n(187Os)/n(186Os) and amount ratio n(187Re)/n(186Os) are used for geochronology; for example, variations in these ratios have been used to determine the ages of the Earth, Moon, and meteorites. Kirk et al. measured rhenium-osmium isotopic abundances in gold and pyrites from conglomerates of the Central Rand Group of South Africa (Fig. IUPAC.76.1), which have produced over 48 000 metric tons of gold and have accounted for 40 percent of the world’s total historic production. The gold and rounded pyrites from the conglomerates yield an age of ~3.0×109 years. Kirk et al. find that this age is much older than that of the conglomerate, and they conclude that the gold is detrital (material wearing away by weathering or erosion) and was not deposited by later hydrothermal fluids.

Isotop osmium lainnya

¹⁶¹Os, ¹⁶²Os, ¹⁶³Os, ¹⁶⁴Os, ¹⁶⁵Os, ¹⁶⁶Os, ¹⁶⁷Os, ¹⁶⁸Os, ¹⁶⁹Os, ¹⁷⁰Os, ¹⁷¹Os, ¹⁷²Os, ¹⁷³Os, ¹⁷⁴Os, ¹⁷⁵Os, ¹⁷⁶Os, ¹⁷⁷Os, ¹⁷⁸Os, ¹⁷⁹Os, ¹⁸⁰Os, ¹⁸¹Os, ¹⁸²Os, ¹⁸³Os, ¹⁸⁴Os, ¹⁸⁵Os, ¹⁸⁶Os, ¹⁸⁸Os, ¹⁸⁹Os, ¹⁹⁰Os, ¹⁹¹Os, ¹⁹²Os, ¹⁹³Os, ¹⁹⁴Os, ¹⁹⁵Os, ¹⁹⁶Os, ¹⁹⁷Os, ¹⁹⁸Os, ¹⁹⁹Os, ²⁰⁰Os, ²⁰¹Os, ²⁰²Os, ²⁰³Os

Pelajari

Kimia inti Simulasi peluruhan ¹⁸⁷Os Bagan nuklida