描述
Cesium, also known as cs or cesio, is a member of the class of compounds known as homogeneous alkali metal compounds. Homogeneous alkali metal compounds are inorganic compounds containing only metal atoms,with the largest atom being a alkali metal atom. Cesium can be found in a number of food items such as almond, white cabbage, dill, and cucumber, which makes cesium a potential biomarker for the consumption of these food products. Cesium can be found primarily in blood, cerebrospinal fluid (CSF), saliva, and urine. Cesium is a non-carcinogenic (not listed by IARC) potentially toxic compound. Caesium or cesium is a chemical element with symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28.5 °C (83.3 °F), which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium has physical and chemical properties similar to those of rubidium and potassium. The most reactive of all metals, it is pyrophoric and reacts with water even at −116 °C (−177 °F). It is the least electronegative element, with a value of 0.79 on the Pauling scale. It has only one stable isotope, caesium-133. Caesium is mined mostly from pollucite, while the radioisotopes, especially caesium-137, a fission product, are extracted from waste produced by nuclear reactors .