They needed a code name since those weapons didn't have nomenclatures.
fat man and little boy
'Little Boy' - Uranium whereas 'Fat Man' used Plutonium triggering devices .
The "Fat Man" and "Little Boy" were the nicknames for the two atomic bombs dropped on the Japanese cities of Hiroshima and Nagasaki. The first one, the "Little Boy," was dropped over Hiroshima on August 6. The second one, the "Fat Man," was dropped over Nagasaki on August 9.
Little boy - Hiroshima - 6 august 1945 Fat man - Nagasaki - 9 august 1945
Little Boy was employed at Hiroshima and Fat Man at Nagasaki.
The two atomic bombs that were dropped on Japan were called "Fat Man" and "Little Boy".
The Little man used uranium as fuel and the Fat man used Plutonium as fuel.
little boy was on Hiroshima and fat man was on nagasaki.
Little boy was dropped over Hiroshima and fat boy was dropped over Nagasaki.
They were called Little Boy and Fat man. (see related question link below)
The fat man and the little boy are atomic bombs made during World War 2.
Little Boy was dropped on Hiroshima Fat Man was dropped on Nagasaki