The Royal Swedish Academy of the Sciences has chosen Penn alumnus Ahmed Zewail (Gr’74) as recipient of the 1999 Nobel Prize in chemistry.

Zewail, a native of Egypt who maintains both American and Egyptian citizenship, is being recognized for his studies of the step-by-step processes of chemical reactions. Chemistry Professor Robin Hochstrasser, under whom Zewail studied at Penn, said that Zewail’s work gives an “understanding of how these reactions work.”

Zewail, a professor of chemistry and physics at California Institute of Technology, will receive the $960,000 award in Stockholm, Sweden, on Dec. 10. In a citation, the Royal Swedish Academy said, “Professor Zewail’s contributions have brought about a revolution in chemistry and adjacent sciences, since this investigation allows us to understand and predict important reactions.”

Zewail began his prize-winning research in the late 1980s with experiments that led to the development of femtochemistry, a field that uses high-speed lasers to take pictures of molecules in the process of undergoing chemical reactions.