Abegg was born in the German port of Danzig (now Gdańsk in Poland); he studied chemistry at Kiel, Tübingen, and Berlin. He graduated in 1891 as a pupil of Wilhelm Hofmann. Initially an organic chemist, he was attracted by the advances being made in physical chemistry, and in 1894 moved to Göttingen as an assistant to Hermann Nernst. Here, he worked on electrochemical and related problems and with G. Bodländer produced an important paper on valence, Die Elektronaffinität (1899; Electron Affinity). He is remembered for Abegg's rule (partially anticipated by Dmitri Mendeleev), which states that each element has two valences: a normal valence and a contravalence, the sum of which is eight. In 1899 he became a professor at Breslau (now Wrocław in Poland) and was about to become the director of the Physico-Chemical Institute there when he was killed in a ballooning accident.