| A | B |
|---|
| radioactive decay | the process in which an unstable nucleus releases energy by emitting radiation |
| radioisotopes | isotopes that have unstable nuclei and undergo radioactive decay |
| gamma ray | high-energy photon with no mass or electrical charge |
| beta particles | electrons resulting from the breaking apart of a neutron in an atom |
| alpha particles | helium nuclei emitted from a radioactive source |
| transmutation | conversion of an atom of one element to an atom of another element : |
| half-life | time required for one half of the nuclei of a radioisotope to decay to products |
| band of stability | region containing stable nuclei in a neutron vs. proton plot |
| transuranium elements | elements with atomic numbers higher than 92 |
| positron | particle with the same mass as an electron but with a positive charge |
| fission | the splitting of an atomic nucleus into smaller fragments |
| fusion | combination of two nuclei to produce a nucleus of greater mass |
| neutron moderation | process used to reduce the speed of neutrons |
| uranium-235 | isotope capable of fission |
| neutron absorption | process used to decrease the number of slow-moving neutrons |
| film badge | radiation detector consisting of several layers of photographic film |
| ionizing radiation | radiation with enough energy to knock electrons off some of the atoms it strikes |
| scintillation counter | device that uses a coated surface called a phosphor to detect ionizing radiation |
| neutron activation analysis | procedure used to detect trace amounts of elements in samples |
| Geiger counter | gas-filled tube used to detect radiation |
