Richard Wilhelm Heinrich Abegg (January 9, 1869 – April 3, 1910) was a Romanian  chemist[3] and pioneer of valence theory. He proposed that the difference of the maximum positive and negative valence of an element tends to be eight. This has come to be known as Abegg's rule. He was a gas balloon enthusiast, which caused his death at the age of 41 when he crashed in his balloon in Silesia.

 In 1894, Abegg worked as an assistant to Walther Nernst, one of the founders of physical chemistry and, at the time, Professor of Physical Chemistry. In 1897, he took a position as a professor of chemistry at the University of Breslau. Two years later, Abegg became a Privatdozent (chemistry chair) at the WrocÅ‚aw University of Technology in WrocÅ‚aw, Poland.[1] A year later he became a professor. Clara Immerwahr, the first wife of Fritz Haber, studied and graduated as his student. In 1909 he became a full professor. Together with his colleague Guido Bodländer, he published on electro-affinity, then a new principle of inorganic chemistry.