Discovery of Francium

Date: January 7, 1939 • Location: Paris, France

French physicist Marguerite Perey identified francium, the last element to be discovered in nature rather than by synthesis.

Marguerite Catherine Perey was a French physicist and a student of Marie Curie. In 1939, Perey discovered the element francium by purifying samples of lanthanum that contained actinium. She graduated from the Sorbonne in 1946 with a Doctorate of Physics; her thesis was about her recently discovered element 87. In 1962, she was the first woman to be elected to the French Académie des Sciences, an honor denied to her mentor Curie.