The bombs that destroyed Hiroshima and Nagasaki used up about a gram of matter each to do so.
The Hiroshima bomb -
Little Boy - Wikipedia:
quote:
The Mk I "Little Boy" was 10 feet (3 m) in length, 28 inches (71 cm) in diameter and weighed 8,900 lb (4000 kg). The design used the gun method to explosively force a hollow sub-critical mass of uranium-235 and a solid target spike together into a super-critical mass, initiating a nuclear chain reaction. This was accomplished by shooting one piece of the uranium onto the other by means of chemical explosives. It contained 64 kg of uranium, of which 0.7 kg underwent nuclear fission, and of this mass only 0.6 g became energy.
The Nagasaki bomb used Plutonium. Wiki didn't have mass conversion information as for the Little Boy.
Fat Man - Wikipedia
Moose
Edited by Minnemooseus, : Changed subtitle.
™ Version 4.2