noun🔗ShareThe 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. "elementchemistrysubstancescienceChat with AIVocabulary GamePractice Reading
noun🔗ShareA 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. "elementchemistrysubstanceChat with AIVocabulary GamePractice Reading
