caesium

== English == === Alternative forms === cæsium (dated) cesium (US) === Etymology === From Latin caesius (“sky-blue”), in reference to the radiation spectra, +‎ -ium. === Pronunciation === enPR: sē'zēəm, IPA(key): /ˈsiːzi.əm/ === Noun === caesium (uncountable) The chemical element (symbol Cs) with an atomic number of 55. It is a soft, gold-colored, highly reactive alkali metal. ==== Derived terms ==== ==== Related terms ==== caesious ==== Translations ==== === See also === lepidolite pollucite === References === Caesium on the British Royal Society of Chemistry's online periodic table === Anagrams === aeciums, æciums == Danish == === Noun === caesium n alternative spelling of cæsium == French == === Noun === caesium m (uncountable) alternative spelling of césium == Latin == === Pronunciation === (Classical Latin) IPA(key): [ˈkae̯.si.ũː] (modern Italianate Ecclesiastical) IPA(key): [ˈt͡ʃɛː.s̬i.um] === Adjective === caesium nominative neuter singular of caesius === Noun === caesium n (genitive caesiī); second declension caesium ==== Declension ==== Second-declension noun (neuter).