name of the two nukes dropped on japan
Atomic bombings of Hiroshima and Nagasaki Working in collaboration with the United Kingdom and Canada, with their respective projects Tube Alloys and Chalk River Laboratories,[55][56] the Manhattan Project, under the direction of Major General Leslie R. Groves, Jr., of the U.S. Army Corps of Engineers, designed and built the first atomic bombs.[57] Groves appointed J. Robert Oppenheimer to organize and head the project's Los Alamos Laboratory in New Mexico, where bomb design work was carried out.[58] Two types of bombs were eventually developed. Little Boy was a gun-type fission weapon that used uranium-235, a rare isotope of uranium separated at the Clinton Engineer Works at Oak Ridge, Tennessee.[59] The other, known as a Fat Man device (both types named by Robert Serber), was a more powerful and efficient, but more complicated, implosion-type nuclear weapon that used plutonium created in nuclear reactors at Hanford, Washington. A test implosion weapon, the gadget, was detonated at Trinity Site, on July 16, 1945, near Alamogordo, New Mexico.[60]