noun. A soft, silvery-white ductile, metallic element that is the most electropositive and alkaline of the elements and is used in atomic clocks and photoelectric cells and to catalyze hydrogenation of some organic compounds. The fundamental unit of time in the International System, the second, is based on the frequency of radiation between two energy states in an atom of the Cs-133 isotope. Atomic number 55; atomic weight 132.905; melting point 28.44°C; boiling point 671°C; specific gravity 1.873; valence 1. cross-reference: Periodic Table.

noun. the chemical element of atomic number 55. It is a univalent element, the most electropositive metal. Symbol Cs; atomic weight 132.905. IT has a melting point of 28.4° C.

noun. Alternative spelling of caesium.

noun. a soft silver-white ductile metallic element (liquid at normal temperatures); the most electropositive and alkaline metal

""It stands to reason that at some point the Ukrainian government would like to be able to use that land again, but the scientists have calculated that what they call cesium's" ecological half-life "- the time for half the cesium to disappear from the local environment - is between"

metal  metallic element  

cesium 137  

magnesium  

alkyl  argon  bromine  cadmium  chlorate  

Cs  caesium