| || ||Uranium is the 92nd element on the periodic table. Its most common isotope, U238 has 92 protons and 146 neutrons, for an atomic weight (mean relative mass) of 238. The first recorded instance of uranium mining was in the beginning of the sixteenth century in the silver mining town of Sankt Joachimsthal. This town was located in the mountains that separated Bohemia from Saxony. The miners discovered a black mineral that they named pechblende, from the German words pech, which means either pitch or bad luck, and blende, meaning mineral. |
In 1789, a German chemist named Martin Klaproth isolated uranium oxide from pitchblende. At the time, he referred to it as "a strange kind of half metal". In a presentation to the Berlin Academy of Sciences on 24 September 1789, he suggested that the new element be called "uran", which later became "uranium". This name came from the latest planet to have been discovered, Uranus. The planet was discovered by William Herschel, who named Uranus after Urania, the muse of astronomy and geometry.
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