What element was used to make the first atomic bomb?

The U.S. developed two types of atomic bombs during the Second World War. The first, Little Boy, was a gun-type weapon with a uranium core. Little Boy was dropped on Hiroshima. The second weapon, dropped on Nagasaki, was called Fat Man and was an implosion-type device with a plutonium core. read more

Many elements were used in the first atomic bombs in the nonnuclear parts. As I cannot possibly list them all (the most common elements were the carbon, nitrogen, and oxygen used in the chemical explosives) I will only address the elements used as the nuclear fuel that powered the atomic explosion. read more

The first atomic bomb tested (Gadget on July 16, 1945) used plutonium as the fission fuel alloyed with gallium and beryllium and polonium in the neutron source initiator. Two explosive mixtures called Composition B and Baratol were used in the explosive lenses that imploded the plutonium to make it supercritical (these explosives contained many elements including: carbon, hydrogen, nitrogen, oxygen, barium, etc.). read more