Rhenium

Rhenium is a chemical element with symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust. The free element has the third-highest melting point and highest boiling point of any element, at 5,869 K (10,105 °F). Rhenium resembles manganese and technetium chemically and is obtained as a by-product of molybdenum and copper ore's extraction and refinement. Rhenium shows in its compounds a wide variety of oxidation states ranging from −1 to +7.

Discovered in 1925, rhenium was the last stable element to be discovered. It was named after the river Rhine in Europe.

Nickel-based superalloys of rhenium are used in the combustion chambers, turbine blades, and exhaust nozzles of jet engines. These alloys contain up to 6% rhenium, making jet engine construction the largest single use for the element, with the chemical industry's catalytic uses being next-most important. Because of the low availability relative to demand, rhenium is among the most expensive of metals, with an average price of approximately US$2,750 per kilogram (US$85.53 per troy ounce) as of April 2015; it is also of critical strategic military importance, for its use in high performance military jet and rocket engines.

Osmium (album)

Osmium is the debut album of American funk band Parliament, led by George Clinton. The album has a psychedelic soul sound with a spirit of experimentation that is more similar to early Funkadelic than the later R&B-inspired Parliament albums. It was originally released in July 1970 on Invictus Records. The original vinyl release contained a glossy lyric sheet.

Since its re-release in 1990, Osmium has been distributed numerous times by various labels in the U.S., Europe and Japan, sometimes under alternate titles that have included Rhenium and First Thangs. A number of these reissues have featured material that was not included on the original album, such as unreleased tracks and singles that were recorded around the same time as Osmium.

The personnel for this album included the five Parliaments singers and the five backing musicians known as Funkadelic. The same personnel also recorded as Funkadelic, releasing that act's self-titled debut album also in 1970. After the release of Osmium, contractual difficulties prevented further recording under the name Parliament until 1974, when Clinton signed that act to Casablanca Records and positioned it as an R&B-inspired counterpoint to the more rock-oriented Funkadelic.

Isotopes of rhenium

Naturally occurring rhenium (Re) is 37.4% ¹⁸⁵Re, which is stable, and 62.6% ¹⁸⁷Re, which is unstable but has a very long half-life (41.2×10⁹ years). Among elements with a known stable isotope, only indium and tellurium similarly occur with a stable isotope in lower abundance than the long-lived radioactive isotope.

There are 33 other unstable isotopes recognized, the longest-lived of which are ¹⁸³Re with a half-life of 70 days, ¹⁸⁴Re with a half-life of 38 days, ¹⁸⁶Re with a half-life of 3.7186 days, ¹⁸²Re with a half-life of 64.0 hours, and ¹⁸⁹Re with a half-life of 24.3 hours. There are also numerous isomers, the longest-lived of which are ^186mRe with a half-life of 200,000 years and ^184mRe with a half-life of 169 days. All others have half-lives less than a day.

Relative atomic mass: 186.207(1).

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