Atomic bomb

The atomic bomb was the name used in the 1950s for the first of what are now called nuclear weapons. It was originally developed out of fear that the Germans were also working on such a weapon (as in fact they were, although they did not get very far with their project.)

The secret wartime project that developed the bomb was called by the code name the Manhattan project. It had nothing to do with Manhattan. Much the development took place at Los Alamos, New Mexico. The town, laboratories, production and test facilities built there for the Manhattan Project became what is today the Los Alamos National Laboratory.

The United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki, bringing World War II to a swift and decisive end.

The atomic bomb detonates with a massive explosion due to the release of energy in atoms. Specifically, neutrons in a rapid chain reaction split the nuclei of a heavy chemical element, such as plutonium or uranium, to cause the massive release of energy.