The discovery of francium?
Francium was discovered by Marguerite Perey in 1939.
Francium was discovered in 1939 by French chemist Marguerite Perey. Francium is one of the rarest elements found on the earths surface and there is less than an ounce of it in the earths crust, therefore, this made it hard for Francium to be discovered, and was finally discovered 80 years after all of the others.
Francium was discovered by chance by Marguerite Perey in 1939 during a study on actinium-227: she observed an energy level of radiation possibly attributable to a new element. After some chemical experiments she was sure that the radiation is from a new chemical element, after this called francium. The atomic number of francium in the periodic table is 87.