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مهر
۹۴
FRANCIUM Fr
Alkali metal. White, very fusible. Radioactive, most lived isotope 223Fr (half-life of 22 min.). The most reactive of all metals, chemical behavior similar to cesium. On the air is covered by an oxide film. A strong reducing agent, reacts vigorously with water, and the acid releasing hydrogen. Cation of Fr+ in the aqueous solution is colorless. In the Earth's lithosphere is formed by the radioactive decay of uranium and actinium. Synthesized by bombardment of uranium nuclei by protons or neutrons nuclei of radium. Isolated compounds FrClO4 and Fr2[PtCl6] by method of coprecipitation with appropriate poorly soluble salts of Rb and Cs.
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- ۲۹ مهر ۹۴ ، ۲۲:۳۵