Uranium
The United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki in August 1945, during the final stage of the Second World War. The two bombings, which killed at least 129,000 people, remain the only use of nuclear weapons for warfare in history. The 509th Composite Group of the U.S. Army Air Forces was equipped with the specialized Silverplate version of the Boeing B-29 Superfortress, that could deliver them from Tinian in the Mariana Islands. On August 6 the U.S. dropped a uranium gun-type atomic bomb (Little Boy) on Hiroshima. Two nuclear weapons were used by the US against Japanese cities at the end of World War 2: Hiroshima On August 6, 1945, at 8:15 AM Tokyo time, a B-29 bomber, the Enola Gay … , piloted by Paul W. Tibbets, dropped a uranium atomic bomb, code named Little Boy on Hiroshima, Japan's seventh largest city.  Little Boy was the codename for the type of atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 by the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul W. Tibbets, Jr. , commander of the 509th Composite Group of the United States Army Air Forces. After the war ended, it was not expected that the inefficient Little Boy design would ever again be required, and many plans and diagrams were destroyed, but by mid-1946 the Hanford Site reactors were suffering badly from the Wigner effect, so six Little Boy assemblies were produced at Sandia Base. It was the first atomic bomb to be used in warfare. The Hiroshima bombing was the second artificial nuclear explosion in history, after the Trinity test, and the first uranium-based detonation. It exploded with an energy of approximately 15 kilotons of TNT (63 TJ). After the war ended, it was not expected that the inefficient Little Boy design would ever again be required, and many plans and diagrams were destroyed, but by mid-1946 the Hanford Site reactors were suffering badly from the Wigner effect, so six Little Boy assemblies were produced at Sandia Base. There are two ways residual radioactivity is produced from an atomic blast. The first is due to fallout of the fission products or the nuclear material itself--uranium or plutonium (uranium was used for the Hiroshima bomb whereas plutonium was used for the Nagasaki bomb)--that contaminate the ground. Hiroshima. On August 6, 1945, a uranium fission bomb was detonated over the Japanese city of Hiroshima. The bomb, called Little Boy was a  gun-type  device which used an explosive charge to force two sub-critical masses of U-235 together. Plutonium Bomb. Plutonium-239 is a fissionable isotope and can be used to make a nuclear fission bomb similar to that produced with uranium-235. The bomb which was dropped at Nagasaki was a plutonium bomb. Not enough Pu-239 exists in nature to make a major weapons supply, but it is easily produced in breeder reactors. On August 6 and 9, 1945, the cities of Hiroshima and Nagasaki were destroyed by the first atomic bombs used in warfare. The first atomic bomb ever to be used in a military operation was dropped on the city of Hiroshima, Japan On August 6, 1945 at 8:16:02 a.m. Hiroshima time. Within the first two to four months of the bombings, the acute effects of the atomic bombings killed 90,000–146,000 people in Hiroshima and 39,000–80,000 in Nagasaki; roughly half of the deaths in each city occurred on the first day. The 509th Composite Group of the U.S. Army Air Forces was equipped with the specialized Silverplate version of the Boeing B-29 Superfortress, that could deliver them from Tinian in the Mariana Islands. On August 6 the U.S. dropped a uranium gun-type atomic bomb (Little Boy) on Hiroshima. The US has dropped atomic bombs in 1945 on two Japanese cities, Hiroshima and Nagasaki. 1 person found this useful. Edit. Share to: Eccles-Jordan Trigger Circuit. 73,446 Contributions. This circuit is used in almost every electronic digital computer ever built & was invented in 1918 (patent GB148582). The US dropped the first atomic bombs on two Japanese cities in 1946, on Hiroshima on August 6 and on Nagasaki on August 9. No other atomic bombs have been dropped on in … habited cities, although several countries have exploded many other atomic bombs in tests. The resulting uranium mass comprised of both projectile and target becomes critical and the chain reaction begins. Dropped on the Japanese city of Hiroshima on August 6, 1945, it was the first nuclear weapon used in a war. 1  Weight: 9,700 lbs. 2  Length: 10 ft.; Diameter: 28 in. 3  Fuel: Highly enriched uranium; Oralloy. 
https://en.wikipedia.org/wiki/Atomic_bombings_of_Hiroshima_and_Nagasaki http://www.answers.com/Q/What_material_was_used_in_the_Nagasaki_bomb https://en.wikipedia.org/wiki/Hiroshima_bomb https://en.wikipedia.org/wiki/Hiroshima_bomb http://www.rerf.jp/general/qa_e/qa12.html http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/bomb.html http://www.world-war-2.info/atomic-bomb/ https://en.wikipedia.org/wiki/Atomic_bombings_of_Hiroshima_and_Nagasaki http://www.answers.com/Q/What_are_the_materials_used_in_an_atomic_bomb http://www.atomicheritage.org/history/little-boy-and-fat-man
what material was used in hiroshima