Francium is a naturally occurring, but extremely rare element, that currently has no real purpose. Continue reading to find out more…
Francium, atomic number 87, is a solid and highly radioactive element. There are no stable isotopes of francium found on Earth. Since all of its 22 isotopes are radioactive, the one with the longest half-life, francium-223, is use to determine the element’s atomic mass. Francium-223 is also the only isotopes of francium that is found naturally in nature. Because of its short half-life, not much is known about its properties. Its melting point is 27˚C and its boiling point is 677˚C, but its density is still unknown. Similar to the other alkali metals, it is assumed that francium has a +1 oxidation state.
Francium’s atoms are the largest and the heaviest of the alkali metals. No one has figured out how to refine it from natural minerals because the atoms of 223francium are scattered very thinly over the Earth’s crust. All of the other 30 isotopes are produce for study by nuclear decay of other radioactive elements. Francium is the only element between atomic numbers 1 and 92 that has a half-life of less than 30 minutes. It is also the only known element that has more identified isotopes that identified compounds. There are two main methods for scientists to create a sample of francium for use. One way is to bombard thorium with protons. The other way is to start with radium in a particle accelerator, where, through a series of decay process, the radium is converted to actinium, which in turn rapidly decays into thorium, and finally, thorium decays naturally into francium.
As all isotopes of francium have very short half-lives, there are few practical uses for it other than a source of radiation to study the radioactive decay process. It has 33 compounds, but yet a lot less compounds. By studying the ways other alkali metals form compounds, we can hypothesize on francium’s possibilities of making them. Its metal ion is most likely Fr+, which means it has a very low level of electronegativity and would combine easily with anions of nonmetals that have a very high electronegativity. Finally, because of francium’s difficulty to find and produce, it makes it almost impossible to consider it harmful to the common people.