Francium (Fr)
Overview of Francium
Francium is a highly radioactive alkali metal with atomic number 87. It is the second-rarest naturally occurring element in Earth’s crust, existing only in trace amounts at any given time. The most stable isotope, francium-223, has a half-life of just 22 minutes, which makes it impossible to collect in visible quantities. Because of its extreme instability, francium has no practical applications beyond research.
How Francium Is Formed
Francium is produced naturally through the radioactive decay of actinium. In laboratory settings, it can be synthesized in small amounts by:
Bombarding radium with neutrons in a nuclear reactor.
Bombarding thorium with protons in a particle accelerator.
Due to its short lifespan and strong radioactivity, francium is highly toxic and studied only under controlled research conditions.
Uses and Biological Role of Francium
Francium has no known uses outside of research, where it is employed to better understand the behavior of alkali metals and heavy elements.
It has no biological role and is extremely toxic due to its intense radioactivity.
History of Francium
Predicted by Mendeleev: When Dmitri Mendeleev created the first periodic table in 1869, he predicted the existence of an element below cesium, which he called eka-cesium. Scientists searched for it for decades.
False claims: Throughout the late 19th and early 20th centuries, several chemists claimed to have discovered element 87, but these were later disproven.
1939 – Discovery: French physicist Marguerite Perey, working at the Curie Institute in Paris, successfully identified francium while studying the decay of actinium. She demonstrated that the new element was indeed the missing alkali metal.
Recognition: Perey’s discovery was confirmed after World War II, and she was officially credited. The element was named francium in honor of France.