Bob Wishowski, age 17, of Springfield, Ill., for his question:

WHO WAS LEO SZILARD?

Leo Szilard was a Hungarian born American nuclear physicist who was noted for his work in the development of controlled nuclear fission.

Born in Budapest in 1898, Szilard was educated at the Budapest Institute of Technology and at the University of Berlin where he received a Ph.D. degree in 1922. In 1938 he came to the United States as a guest researcher at Columbia University and in the following year he was one of the scientists who persuaded Albert Einstein to write to President Franklin D. Roosevelt urging exploration of the military potential of atomic energy.

In 1942 at the University of Chicago, Szilard, with the Italian physicist Enrico Fermi, created the first nuclear chain reaction.

Szilard made important contributions to the development in 1945 of the first atomic bomb, but protested the decision to bomb Hiroshima and Nagasaki, Japan. Thereafter he was active in efforts to restrict the use of atomic energy to peaceful purposes.

Szilard became a naturalized U.S. citizen in 1943. In 1946 he became a professor of biophysics at the University of Chicago. He died in La Jolla, Calif. in 1964.