| A | B |
|---|
| strong force | attractive force that acts between protons and neutrons in an atomic nucleus |
| radioactivity | process that occurs when a nucleus decays and emits alpha, beta, and gamma radiation |
| alpha particle | particle consisting of two protons and two neutrons that is emitted from a decaying atomic nucleus |
| transmutation | process of changing one element to another through radioactive decay |
| beta particle | electron that is emitted from a decaying atomic nucleus |
| gamma ray | electromagnetic wave with no mass and no charge that travels at the speed of light and is usually emitted with alpha or beta particles from a decaying atomic nucleus; has a wavelength less than about ten trillionths |
| half-life | amount of time it takes for half the nuclei in a sample of a radioactive isotope to decay |
| cloud chamber | radiation detector that uses water or ethanol vapor to detect the paths of charged particles |
| bubble chamber | radiation detector, consisting of a container of superheated liquid under pressure, that is used to detect the paths of charged particles |
| Geiger counter | radiation detector that produces a click or a flash of light when a charged particle is detected |
| nuclear fission | process of splitting an atomic nucleus into two or more nuclei with smaller masses |
| chain reaction | ongoing series of fission reactions |
| critical mass | amount of fissionable material required so that each fission reaction produces approximately one more fission reaction |
| nuclear fusion | reaction in which two or more atomic nuclei form a nucleus with a larger mass |
| tracer | radioactive isotope, such as iodine-131, that can be detected by the radiation it emits after it is absorbed by a living organism |
