noun🔗Share钫 (fāng) The chemical element (symbol Fr) with an atomic number of 87. It is an intensely radioactive alkali metal that is not found in nature."Because francium is intensely radioactive and extremely rare, scientists must create it artificially in laboratories for research. "由于钫具有极强的放射性并且极其稀有，科学家们必须在实验室里人工合成它来进行研究。elementchemistrysubstancescienceChat with AIVocabulary GamePractice Reading
noun🔗Share钫原子 A single atom of this element."Because francium is so rare and unstable, seeing even a single atom of francium is an accomplishment in a laboratory. "由于钫非常稀有且不稳定，所以在实验室里能观察到一个钫原子都是一项成就。elementchemistrysubstanceChat with AIVocabulary GamePractice Reading
