Technetium is a chemical element in the periodic table that has the symbol Tc and atomic number 43. The chemical properties of this silvery gray, radioactive, crystalline transition metal are intermediate between rhenium and manganese. Its short-lived isotope Tc-99m is used in nuclear medicine to diagnose certain cancers, Tc-99 is used as a gamma ray-free source of beta rays, and its pertechnate ion could find use as a corrosion preventer for steel (this possible use is hindered by technetium's radioactivity). Dmitri Mendeleev predicted many of the properties of element 43, which he called ekamanganese, well before its actual discovery. In 1937 its isotope Tc-97 became the first element to be artificially produced, hence its name (from the Greek technètos, meaning "artificial"). Most technetium produced on Earth is a by-product of fission of uranium-235 in nuclear reactors and is extracted from nuclear fuel rods. On earth, technetium occurs naturally only in uranium ores as a product of spontaneous fission; the quantities are infinitesimal but have been measured.

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_______________________________ Today's selected anniversaries:

455: The Vandals plundered Rome. (http://en.wikipedia.org/wiki/Vandals)

1800: The first smallpox vaccination was administered in North America. (http://en.wikipedia.org/wiki/smallpox)

1865: Forces under General Edmund Kirby Smith became the last Confederate army to surrender in the American Civil War. (http://en.wikipedia.org/wiki/Edmund_Kirby_Smith)

1946: Birth of the Italian Republic: Italy became a republic and abolished the monarchy, exiling Umberto. (http://en.wikipedia.org/wiki/Birth_of_the_Italian_Republic)

1953: Coronation of Queen Elizabeth II of the United Kingdom, the first to be televised. (http://en.wikipedia.org/wiki/Elizabeth_II_of_the_United_Kingdom)

_____________________ Wikiquote of the day:

"I'm the guy they used to call Deep Throat." -- W. Mark Felt (http://en.wikiquote.org/wiki/W._Mark_Felt)