| proton | Definition | nucleus |
| Alpha particle | weakest type of nuclear radiation; consists of helium nucleus released during alpha decay | |
| Artificial Transmutation | changing of one element into another by unatural means;involves bombarding a nucleus with high-energy particles to cause a change | |
| Gamma Ray | high-frequency electromagnet wave released during gamma decay; strongest type of nuclear radiation | |
| Beta particle | electron, created in the nucleus of an atom, released during beta decay | |
| Binding energy | energy required to break up a nucleus into its component protons and neutrons | |
| Decay Series | sequence of steps by which a radio active nucleus decays into a non radioactive nucleus | |
| Half-life | amount of time it takes for half of the atom in a given sample of an element to decay | |
| Radioactive decay | process in which a nucleus spontanteously emits particles or rays to become lighter and more stable | |
| Radioactivity | release of energy and matter that results from changes in the nucleus of an atom | |
| Tracer | radioactive element whose pathway can be followed through the steps of a chemical reaction or industrial process | |
| Transmutation | process in which one element is changed into another as a result of changes in the nucleus. | |
| Nuclear Chain Reaction | series of fission reactions that occur because the products released during one fission reaction cause fission reactions in other atoms | |
| Nuclear Fission | splitting of an atomic nucleus into two smaller nuclei of approximately equal mass | |
| Nuclear Fusion | joining of two atomic nuclei of smaller mass to form a single nucleus of larger mass | |
| Trasuranium Element | element formed synthetically; has more than 92 protons in its nucleus | |
| Critical Mass | The smallest mass of a fissionable material that will sustain a nuclear chain reaction at a constant level | |
| Nuclear Reactor | any of several kinds of apparatus that maintain and control a nuclear reaction for the production of energy or artificial elements | |
