Chemist, born in Budapest, Hungary. He studied at Berlin and Freiberg, worked at Manchester under Rutherford (1911), then with Paneth at Vienna (1912-20). In 1923 he discovered, with the Dutch physicist Dirk Coster (1889-1950), the element hafnium at Copenhage (Hafnia being the Latin name for the city). He was a professor at Freiburg Univeristy from 1926, but during World War 2 went to Sweden, where he became professor at Stockholm. He was awarded the 1943 Nobel Prize for Chemistry for his work on isotopic tracer techniques.