Francium 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's most stable isotope, Francium-223 only has a half-life of 22 minutes.

钫的最稳定的同位素，钫- 223也只有22分钟的半衰期。

Because Francium 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。

Gallium is solid at room temperature but will melt if held in your hand, caesium (Cs), and francium (Fr) ?the second rarest naturally occurring element, can also be liquid at or near room temperature.

金属镓在室温里是固体状态但是把它放在你的手上它就会融化，金属铯，元素钫这些比较稀有的元素在室温或者接近室温的情况下是液体状态的。