just watching a history programme and they state that the bomb weighed 4 tons. I know uranium is the heaviest element but how much would the uranium in this bomb weigh? Surely not 4 tons and if not what was the remainder of the weight made up off, could it have been a lead casing for example?
Approximately 13 pounds (6.1 kilograms) of plutonium were used for the Hiroshima bomb... the rest being casing and triggering mechanisms... (Source: Wisconsin Project on Nuclear Arms Control )
I think the Hiroshima bomb was 60kg of high enriched uranium - the Nagasaki bomb was 6kg plute 239.
The rest was reflectors,sheilding, high explosives and casing. Ace