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.
The first bomb was exploded over Hiroshima on August 6, 1945, and a second was dropped on Nagasaki on August 8. The Japanese quickly surrendered. Although other nations have developed atomic weapons and nuclear technology since 1945, Truman remains the only world leader to have ever used an atomic bomb against an enemy.resident Harry Truman learns the full details of the Manhattan Project, in which scientists are attempting to create the first atomic bomb, on this day in 1945.