Nuclear Weapons and Their Effects
A nuclear explosion is caused by the release of energy in an atom, either through fission or fusion. Fission weapons cause an explosion by the splitting of atomic nuclei. This happens when a neutron collides with the nucleus of an atom. The protons in the nucleus are transformed into a great amount of energy and two or three more neutrons are sent out, which go on to split other nuclei. If this continues, a chain reaction will occur. The result is a gigantic explosion. To form a chain reaction, a certain amount of material is needed. This amount is known as the critical mass. If the amount is too small it is called a subcritical mass. The critical mass of a material depends on its purity. The materials used in making fission weapons are uranium and plutonium. They are the only elements able to be used in making a fission weapon. The destructive power in fusion weapons comes from the combining of very light atoms, such as hydrogen. The atoms of the element are fused, and they release a great amount of energy. The element must first be heated to a temperature of 50 million degrees Celsius. The only way to do this, without using more energy than is produced, is to use a fission explosion. So, a ball of hydrogen is surrounded by either uranium or plutonium and then by a non-nuclear explosive. The explosive is set off, and it causes the uranium or plutonium to react through fission, which in turn causes the hydrogen to fuse. Once again, the result is a colossal explosion meant for mass destruction. The three main effects that would follow a nuclear explosion are blast, thermal radiation or heat, and radiation. The very first thing to happen is the formation of a fireball. The fireball gives off the thermal radiation that cremates anything within a quarter mile and ignites any and all flammable materials within ten miles. The thermal radiation can cause eye injuries as well as skin burns called flash burns. Between 20 and 30 percent of the deaths at Hiroshima and