How many atomic bombs did the United States build in World War II?

Three are "thin", "fat" and "little boy". The thin man was an experimental bomb, and the fat man and the little boy were dropped in Nagasaki and Hiroshima, Japan respectively.

■ thin man

On July 6, 2005, the United States tested the code name 1945, one of the three atomic bombs first developed in the world, in the desert area near Alamogodo, New Mexico, USA.

■ Little boy

The code name 1945, one of the first three atomic bombs developed by the United States in the world, was used in Hiroshima, Japan. This is a nuclear bomb made of uranium, with a length of 2.5 meters, a maximum outer diameter of 0.7 1 m, a weight of 4. 1 ton and a power of less than 20,000 tons of TNT equivalent. Because it was much smaller than another nuclear bomb "Fat Man" at that time, it was codenamed "Little Boy".

■ Fat man

The code name of one of the first three atomic bombs developed by the United States in the world was used in Nagasaki, Japan on August 9, 1945. This is an atomic bomb made of plutonium, with a length of about 3.3 meters, a maximum outer diameter of 1.5 meters, a weight of about 4.5 tons and a power of 20,000 tons of TNT equivalent. Because of its bulky size, it is code-named "Fat Man".