Jáchymov 227 zentners [11.35 tonnes] were produced), nickel, bismuth and uranium ore were also extracted. There were also other industries: an enormous tobacco factory employed 1,000 women. In addition, there was the manufacture of gloves and corks and of bobbin lace. On 31 March 1873 the town almost entirely burnt down. At the end of the 19th century, Marie Curie discovered, in tons of pitchblende ore containing uraninite from Joachimsthal, the element radium, for which she won the Nobel Prize in Chemistry. Until the First World War this was the foremost source of radium in the world. The first radon spa
Uranium tungsten and gold (19.3 g/cm). Uranium metal reacts with almost all non-metal elements (with the exception of the noble gases) and their compounds, with reactivity increasing with temperature. Hydrochloric and nitric acids dissolve uranium, but non-oxidizing acids other than hydrochloric acid attack the element very slowly. When finely divided, it can react with cold water; in air, uranium metal becomes coated with a dark layer of uranium oxide. Uranium in ores is extracted chemically and converted into uranium dioxide or other chemical forms usable in industry. Uranium-235 was the first isotope that was found to be fissile. Other naturally occurring