When uranium splits (undergoes fission) it releases 3 neutrons that collide with other uranium atoms, thus creating a chain reaction. Some isotopes can be split too readily, so fast that a continuous fission reaction can’t be maintained. This is called spontaneous fission; the plutonium isotope 240Pu is such an isotope, unlike the isotope 239Pu with its slower fission rate.
This method was used to create the 235U atomic bomb dropped on Hiroshima. A gun-like weapon with a uranium core fired 235U atoms at another piece of 235U-bearing material fast enough to have the neutrons they released naturally slam into the nuclei of other 235U atoms and break them apart. The neutrons released when the atoms split would, in turn, strike and split other 235U atoms. The end result was a massive explosion.
Protons. These subatomic particles have mass and a positive charge. The number of protons in an atom determines what element the atom is. Neutrons. These subatomic particles have the mass as protons but no charge. Alpha particles. These particles are the nuclei of helium atoms, shorn of their orbiting electrons. They consist of 2 protons and 2 neutrons.
Gas Diffusion Centrifuge Electromagnetic Separation Liquid Thermal Diffusion
This method was used to create the 239Pu atomic bomb dropped on Nagasaki. Conventional explosives ringed a mass of plutonium; when detonated, they pushed the plutonium mass together, bringing the 239Pu atoms close enough together that the neutrons they released would continuously strike and split other plutonium atoms. This created an enormous explosion.
