Lise Meitner , born Elise Meitner, 7 November 1878 – 27 October 1968) was an Austrian-Swedish physicist who was one of those responsible for the discovery of the element protactinium and nuclear fission . While working on radioactivity at the Kaiser Wilhelm Institute of Chemistry in Berlin, she discovered the radioactive isotope protactinium-231 in 1917. In 1938, Meitner and her nephew, the physicist Otto Robert Frisch , discovered nuclear fission . She was praised by Albert Einstein as the "German Marie Curie ".