What are atomic bombs made of?

Answer 1

Uranium-253

Uranium-235 needed to make a bomb:

- 15 kilograms: Weight of a solid sphere of 100 percent uranium-235 just large enough to achieve a critical mass with a beryllium reflector. Diameter of such a sphere: 4.48 in (11.4 cm). Diameter of a regulation softball: 3.82 in (9.7 cm).

- 16 kilograms: Amount needed for an Iraqi bomb design found by UN inspectors.

- 50 kilograms: Weight of a solid sphere of 100 percent uranium-235 just large enough to achieve a critical mass without a reflector. Diameter of such a sphere: 6.74 in (17.2 cm), comparable to an average honeydew melon.

- 60 kilograms: Reported amount used in Hiroshima bomb "Little Boy."

Answer 2

Atomic bombs are typically made of either uranium-235 or plutonium-239, both of which are fissile materials capable of sustaining a chain reaction. These materials undergo a process called nuclear fission when the bomb is triggered, releasing an immense amount of energy in the form of heat, blast, and radiation. Surrounding the fissile core is a layer of conventional explosives that compress the core to achieve critical mass and initiate the chain reaction.