| A | B |
|---|
| beta particle | a fast-moving electron formed by the decomposition of a neutron |
| half-life | the time required for one-half of the atoms of a radioisotope to emit radiation and to decay to products |
| gamma radiation | the most penetrating radiation, high-energy photon with no mass or electrical charge |
| Geiger counter | uses a gas- filled metal tube to detect radiation |
| film badge | several layers of photographic film covered with black light-proof paper encased in a plastic or metal holder |
| radiation | the penetrating rays emitted by a radioactive source |
| alpha particle | a particle that has two protons and two neutrons, helium nuclei emitted from a radioactive source |
| radioisotopes | isotopes that have unstable nuclei and undergo radioactive decay |
| radioactive decay | the process in which an unstable nucleus releases energy by emitting radiation |
| positron | particle with the same mass as an electron but with a positive charge |
| transmutation | conversion of an atom of one element to an atom of another element |
| uranium-235 | isotope capable of fission |
| fission | the splitting of an atomic nucleus into smaller fragments |
| fusion | combination of two nuclei to produce a nucleus of greater mass |
