From the Latin CAESIUS, BLUE SKY, element of atomic number 55 in the Periodic Table, belongs to the Alkaline number, discovered in 1860 by Bunsen who also discovered the Rubidium.
It is found in nature in small amounts in Feldspar, mineral waters. An example of a typical mineral is Pollucite (Aluminum Double Silicate and to (Cs), in contrast to Rubidium and Potassium, it does not show any radiation, or perhaps it is so weak that it can not be observed by current methods to investigate radiation Beta.
The melting point of the Cesium element is 28.45 C degrees and can be sublimated by special treatment. It is noteworthy that due to this low melting point, the Cesium element changes state to the single contact of the human body. It is also soluble in water so that molecular dispersion is carried out in our body with great ease.
The Cesium serves to build photoelectric cells of emission of electrons (Electric eye), for its property of emitting electrons, when exposed to light, even low frequency (in the visible field).
In moist air, both Rubidium and Cesium spontaneously ignite. Cesium can occur in the form of crystals, forming nitrates or sulfides. The use of Cesium in the operation of ionic rocket rays is prepared; apart it is already used in the space flights of the North American ships Saturn. Cesium 137 or Radioactive Cesium, has about 33 years of half-life, which indicates as a safe replacement (in medicine) of Cobalt. This material is also used in the cooling processes of thermonuclear power stations; This material is produced in the Uranium and Plutonium reactors.