Cesium

Cesium is used as a "getter" (absorber of unwanted gases) in electron tubes because of its affinity for oxygen.   It is also used in photoelectric cells and as a catalyst in the hydrogenation of some organic compounds.   It is used in atomic clocks which are accurate to 5 seconds in 300 years.  Cesium hydroxide (CsOH), the strongest base known, attacks glass.   The most common compounds of cesium are cesium chloride, used to kill cancer cells, and cesium nitrate, used in electron tube filaments, pyrotechnics, and catalysis. ^{Lide 4-8}

Cesium was discovered in 1860 by Bunsen and Gustav Kirchhoff, a German physicist, in mineral water from Durkheim, Germany.   Cesium is found in lepidolite, pollucite and other ores.   Cesium can be prepared by electrolysis of the fused cyanide and by thermal decomposition of cesium azide. ^{Lide 4-8}