3 August 2023
Francium is a chemical element with atomic number 87 and symbol Fr. It is extremely radioactive, and only two of its thirty-seven known isotopes are found in nature. Its most stable isotope, Francium-233, has a half-life of only 22 minutes. Francium has no applications other than research. It is, obviously, named for the country of France.
It was discovered by physicist Marguerite Perey in 1939, and she originally dubbed it actinium K, in accordance with the then-current system for naming radioactive isotopes. But with the determination that it was a new element, a new name was required. In her 1946 doctoral thesis she proposed the name Francium and the symbol Fa. The suggestion for the symbol, however, was altered to Fr when officially adopted later that year.
Sources:
Miśkowiec, Pawel. “Name Game: The Naming History of the Chemical Elements—Part 3—Rivalry of Scientists in the Twentieth and Twenty-First Centuries.” Foundations of Chemistry, 12 November 2022. DOI: 10.1007/s10698-022-09452-9.
Oxford English Dictionary, third edition, September 2009, s.v. francium, n.
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