Question

1.

1. From there, describe how an atom bomb is made and how it can produce such devastating destruction.

Answer 1

The immense destructive power of atomic weapons derives from a sudden release of energy produced by splitting the nuclei of the fissile elements making up the bombs' core. The U.S. developed two types of atomic bombs during the Second World War. The first, Little Boy, was a gun-type weapon with a uranium core. Little Boy was dropped on Hiroshima. The second weapon, dropped on Nagasaki, was called Fat Man and was an implosion-type device with a plutonium core.

Atomic bombs are made up of a fissile element, such as uranium, that is enriched in the isotope that can sustain a fission nuclear chain reaction. When a free neutron hits the nucleus of a fissile atom like uranium-235 (235U), the uranium splits into two smaller atoms called fission fragments, plus more neutrons. Fission can be self-sustaining because it produces more neutrons with the speed required to cause new fissions. This creates the chain reaction.

The uranium-235 content of “weapons-grade” uranium is generally greater than 85 percent, though inefficient weapons, deemed “weapons-usable,” can be made of 20 percent enriched uranium. The very first uranium bomb, Little Boy, dropped on Hiroshima in 1945, used 64 kilograms of 80 percent enriched uranium.

In fission weapons, a mass of fissile material, either enriched uranium or plutonium, is assembled into a supercritical mass—the amount of material needed to start an exponentially growing nuclear chain reaction. This is accomplished either by shooting one piece of sub-critical material into another, termed the “gun” method, or by compressing a sub-critical sphere of material using chemical explosives to many times its original density, called the “implosion” metho