Francium(Fr) is the densest of the Alkali Metals and also radioactive. 钫是碱金属中密度最大的,具有放射性。
Even Francium(Fr)'s most stable isotope, Francium(Fr)-223 only has a half-life of22 minutes. 钫的最稳定的同位素,钫-223也只有22分钟的半衰期。
Any of the monovalent metals of group I of the periodic table ( lithium or sodium or potassium or rubidium or cesium or francium ). 周期表中I族的任何单价金属(锂、钠、钾、铷、铯和钫)。
The half-life of francium is 22 minutes. 钫的半衰期是22分钟。
Because Francium(Fr) is mainly only found synthetically in laboratory research, it has no known use outside of the laboratory. 由于钫主要仅在实验室研究中产生,它在实验室外没有已知的用途。