francium | (n) a radioactive element of the alkali-metal group discovered as a disintegration product of actinium, Syn. Fr, atomic number 87 |
钫 | [钫 / 鈁] francium Fr, unstable alkali metal 鹼性金屬|碱性金属 with atomic number 87, disintegration product of actinium 錒|锕 #56,032 [Add to Longdo] |