The first nuclear fission bomb is exploded at the Trinity test site, about sixty miles Northwest of Alamogordo, New Mexico. Fission bombs are also known as atom bombs and create energy by splitting the nucleus of heavy elements such as Uranium and Plutonium.

Uranium
Plutonium

Further info:



Visual Elements - http://www.chemsoc.org/viselements


Outline History of Nuclear Energy - http://www.uic.com.au/nip50.htm