Francium
Francium is a radioactive metal that is found in the earth’s crust. It is the most radioactive element in the earth’s crust and it has a very short half-life. Francium is a soft, silvery-white metal that is very unstable. It is not found in nature in its free state, but it is found in the mineral cleveite. Francium is used in research and in the production of radioactive isotopes.
