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.
It was developed first by the Manhattan Project in the early 1940s in the United States as a way to end World War II, which it did when dropped on the Japanese cities of Hiroshima and Nagasaki.
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.
