Fissile materials can sustain nuclear chain reactions. Most fissionable materials that are not fissile cannot sustain chain reactions. The amount of time it takes half of a given quantity of a radioactive element to decay. Isotopes of elements have the same atomic numbers, but different mass numbers. A material used in a nuclear reactor to slow down the fast neutrons emitted in the process of fission.
Free neutrons decay into a proton, an electron and an anti-neutrino.
A neutron is about 1,838 times heavier than an electron. The splitting of a nucleus of a heavy element into two lighter nuclei, generally accompanied by the release of one or more neutrons and energy. An elementary particle with a positive charge equal to that of an electron, but which is about 1,836 times heavier than an electron. The process of making glass. In the context of plutonium and nuclear waste management, it means the mixing of a material with molten glass in order to render it immobile, safe for storage, and not easily usable for weapons.