Caesium (IUPAC spelling; cesium in American English) is a chemical element; it has symbol Cs and atomic number 55. It is a soft, silvery-golden alkali...

Caesium-137 (137 55Cs ), cesium-137 (US), or radiocaesium, is a radioactive isotope of caesium that is formed as one of the more common fission products...

Caesium (55Cs) has 41 known isotopes, the atomic masses of these isotopes range from 112 to 152. Only one isotope, 133Cs, is stable. The longest-lived...

The caesium standard is a primary frequency standard in which the photon absorption by transitions between the two hyperfine ground states of caesium-133...

22 minutes. It is the second-most electropositive element, behind only caesium, and is the second rarest naturally occurring element (after astatine)...

fixed numerical value of the caesium frequency, ΔνCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9192631770...

Caesium chloride or cesium chloride is the inorganic compound with the formula CsCl. This colorless salt is an important source of caesium ions in a variety...

chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). Together with hydrogen they constitute group 1...

the caesium frequency, Δ ν Cs {\displaystyle \Delta \nu _{\text{Cs}}} , the unperturbed ground-state hyperfine transition frequency of the caesium-133...

of caesium are known. Caesium oxide may refer to: Caesium suboxides (Cs7O, Cs4O, and Cs11O3) Caesium monoxide (Cs2O, the most common oxide) Caesium peroxide...