Io is slightly larger than the Moon. It has a mean radius of 1,821.3 km (1,131.7 mi) (about 5% greater than the Moon's) and a mass of 8.9319 Ã 10 kg (about 21% greater than the Moon's).
Leo Szilard invented the atomic bomb and reactor in 1933 as a more efficient method of transmuting elements. It took another 12 years plus a $2,000,000,000 investment by the US to build the first bombs. A patent for an atomic bomb was awarde â¦ d to Leo Szilard in 1934. That patent is regarded as the invention of the atomic bomb.   He immediately tried to turn the patent over to the British government as a gift.
Roosevelt agreed and placed General Leslie Groves and physicist J. Robert Oppenheimer in charge of the Manhattan Project two years later. The name Manhattan Project was the code word for the development of the atomic bomb. On July 16, 1945, the first atomic bomb was tested at the Trinity Site in New Mexico.The weapon was later used against the Japanese to end World War II.eginning in June 1942 during World War II, the United States' Manhattan Project brought together scientists and military experts to create the world's first atomic bomb.