William Draper Harkins

Harkins, William Draper (1873–1951), U.S. chemist who predicted the existence of the neutron (1927) and theorized the possibility of nuclear fusion: the combination of 4 hydrogen atoms to become 1 helium atom with a minute extra mass converted into energy. He was the first to propose that this fusion process fueled stars.

See also: Fusion; Neutron.