<P> The 1943 Quebec Agreement merged the nuclear weapons projects of the United Kingdom and Canada , Tube Alloys and the Montreal Laboratory , with the Manhattan Project , under the direction of Major General Leslie R. Groves , Jr. , of the U.S. Army Corps of Engineers . 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 . Two types of bombs were eventually developed , both named by Robert Serber. 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 . The other , known as a Fat Man device , was a more powerful and efficient , but more complicated , implosion - type nuclear weapon that used plutonium created in nuclear reactors at Hanford , Washington . </P>
<P> The 1943 Quebec Agreement merged the nuclear weapons projects of the United Kingdom and Canada , Tube Alloys and the Montreal Laboratory , with the Manhattan Project , under the direction of Major General Leslie R. Groves , Jr. , of the U.S. Army Corps of Engineers . 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 . Two types of bombs were eventually developed , both named by Robert Serber. 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 . The other , known as a Fat Man device , was a more powerful and efficient , but more complicated , implosion - type nuclear weapon that used plutonium created in nuclear reactors at Hanford , Washington . </P>
what is the name of the two atomic bombs dropped on japan
what is the name of the two atomic bombs dropped on japan
Little Boy Fat Man
Little Boy Fat Man