In 1929, he obtained the title of chemical laboratory technician at the Women's Technical School and began working at the Paris Radio Institute, where he had obtained a 3-month internship contract as a laboratory technician. When he arrived on the first day he met a very friendly lady dressed in work clothes whom he took to be the laboratory secretary. He soon realized that this simple lady was Marie Curie, professor at the Sorbonne, with two Nobel prizes and founder of the Radium Institute. He made her her personal lab assistant and busied herself with training her. They would be together for five years, until Marie's death.
In 1934 she was appointed radiochemist at the Institute, going on to work under the new director of the Institute, André Debierne, and Irène Joliot-Curie who were interested in the study of actinium.
On January 7, 1939, he observed an anomalous radiation in actinium, which he attributed to a new element, 87, which had the properties corresponding to an alkaline and which he would initially call Actinium K. He had just discovered the last natural element left to complete the Mendeleev's 92-element periodic table. In the 1940s, Coryell and Segrè artificially obtained promethium (61) and astatine (85).
The members of the institute thought that he would present it as his doctoral thesis, as Marie had done with radium. The problem wasn't just that Marguerite didn't have a college degree, it was that she didn't even have a high school diploma. At her Institute they decided to remove her from all laboratory tasks and got her a scholarship so that she could study at the Sorbonne. She attended pre-med in order to gain access to a bachelor's degree and then modules in chemistry, biology and physiology that the university deemed equivalent to a bachelor's degree (Marguerite's case was exceptional in every way).
Finalmente, el 21 de marzo de 1946, a los 36 años, Marguerite presentó su tesis sobre “L’élément 87: Actinium K”. Su última frase recogía el privilegio del descubridor: “El nombre Francio, Fa, se propone para el lugar 87” (hoy día el símbolo del francio es Fr).
She did not win a Nobel Prize, but in 1962 she became the first woman elected to the Paris Academy of Sciences, something not even Marie Curie.
If you want to know more about this great scientist, click on the following link: Marguerite-Catherine Perey