noun🔗Share铯 The chemical element (symbol Cs) with an atomic number of 55. It is a soft, gold-colored, highly reactive alkali metal."Example Sentence: "Because caesium is so reactive, scientists must handle it carefully in special environments to prevent dangerous reactions." "由于铯的反应性非常强，科学家们必须在特殊的条件下小心处理它，以防止发生危险的反应。elementchemistrysubstancematerialscienceChat with AIVocabulary GamePractice Reading
