Perey

The French chemist Marguerite Perey, a protégée of Marie Curie, discovered an element of her own, in 1939.

Perey, being French, decided to call it francium instead.

Marguerite Perey is an exception: the French physicist is considered the sole discoverer of element 87, francium, in 193912.

Perey joined Marie Curie’s institute in Paris at the age of 19 as a lab technician, under the direction of Irène Joliot-Curie and André Debierne.

Because neither could agree about whom Perey was working for at the time, each was unable to claim a role in the discovery.