Brigitte Van Tiggelen

After 150 years of scientific developments, the periodic system of chemical elements is still an icon of modern science. Its resilience is striking. The icon used today by scientists and teachers is in fact the outcome of many rearrangements and reinterpretations by the scientific community during that period. This success is often explained as a result of the underlying atomic structure, discovered in the first decades of the 20th century, an explanation that completely neglects the fine structure of the process of ongoing renegotiation and successive stabilizations. How did indeed contemporary scientists navigate in times of reinterpretation? The physicist Lise Meitner and the chemist Ida Noddack were, in different ways, involved in discoveries and interpretations of the periodic system. In 1934, as part of the celebration of the centenary of Dmitri Mendeleev's birth, they each published an article on the system: Meitner in Die Naturwissenschaften, and Noddack in Angewandte Chemie. These two articles, written from the perspectives of a nuclear physicist and a chemist experienced in searching for undiscovered elements, respectively, constitute excellent sources for understanding what new discoveries and insights meant for the meaning and value of the periodic system at the very beginning of the nuclear age in science. Through an analysis of the two contributions, we will argue that resilience is the foremost value of the periodic system. We will also discuss what this value means for the future of the periodic system and its representations.