when was the nuclear weapon invented
The only countries known to have detonated nuclear weaponsâand acknowledge possessing themâare (chronologically by date of first test) the United States, the Soviet Union (succeeded as a nuclear power by Russia), the United Kingdom, France, the People's Republic of China, India, Pakistan, and North Korea.n 6 August 1945, the U.S. Army Air Forces detonated a uranium gun-type fission bomb over the Japanese city of Hiroshima; three days later, on 9 August, the U.S. Army Air Forces detonated a plutonium implosion-type fission bomb codenamed  Fat Man  over the Japanese city of Nagasaki.