Ahmed Hassan Zewail (born February 26, 1946) is an Egyptian scientist, known as the "father of femtochemistry", he won the 1999 Nobel Prize in Chemistry for his work on femtochemistry and became the first Egyptian scientist to win a Nobel Prize in a scientific field. He is the Linus Pauling Chair Professor Chemistry, Professor of Physics and the director of the Physical Biology Centre for the Ultrafast Science and Technology (UST) at the California Institute of Technology.He won Priestley Medal in 2011.