Intelligence and IQ

What American chemist, born on this day in 1916,  designed and built detectors that identified the existence of plutonium? On March 28, 1941, while World War II was raging in Europe, he and physicist Emilio Segré demonstrated that plutonium-239 was fissile. This meant that a lump of plutonium-239 bombarded by a low velocity neutron, could trigger a chain reaction that would release huge amounts of nuclear energy. This meant that plutonium-239 could replace uranium-235 as the material used in a nuclear bomb.