Nobel Peace Prize for the abolition or reduction of standing armies and for the holding and promotion of peace congresses". Alfred Nobel's will further specified that the prize be awarded by a committee of five people chosen by the Norwegian Parliament. Nobel died in 1896 and he did not leave an explanation for choosing peace as a prize category. As he was a trained chemical engineer, the categories for chemistry and physics were obvious choices. The reasoning behind the peace prize is less clear. According to the Norwegian Nobel Committee, his friendship with Bertha von Suttner, a peace activist and later recipient of
Marie Curie theory of "radioactivity" (a term that she coined), techniques for isolating radioactive isotopes, and the discovery of two elements, polonium and radium. Under her direction, the world's first studies into the treatment of neoplasms were conducted using radioactive isotopes. She founded the Curie Institutes in Paris and in Warsaw, which remain major centres of medical research today. During World War I, she developed mobile radiography units to provide X-ray services to field hospitals. While a French citizen, Marie Skłodowska Curie, who used both surnames, never lost her sense of Polish identity. She taught her daughters the Polish language and took