francium造句
1. The half - life of francium is 22 minutes.
2. Because Francium is mainly only found synthetically in laboratory research, it has no known use outside of the laboratory.
3. Even Francium's most stable isotope, Francium - 223 only has a half - life of 22 minutes.
4. Francium is the densest of the Alkali Metals and also radioactive.
5. Any of the monovalent metals of group I of the periodic table (lithium or sodium or potassium or rubidium or cesium or francium).
6. So little is known about it, because there is only about 1 ATOM OF FRANCIUM IN A CUBIC FOOT OF URANIUM ORE!
7. 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.
8. The cesium-radon period also includes the lanthanides, and the period beginning with francium includes the actinides.