| A | B |
|---|
| radioactivity | process by which an unstable atomic nucleus emits charged particles and energy |
| radioisotope | any atom containing an unstable nucleus |
| nuclear radiation | charged particles and energy that are emitted from the nuclei of radioisotopes |
| alpha particle | positively charged particle made up of two protons and two neutrons |
| background radiation | nuclear radiation that occurs naturally in the environment |
| gamma ray | a penetrating ray of energy emitted by an unstable nucleus |
| beta particle | an electron emitted by an unstable nucleus |
| half-life | the time required for one half of the sample of a radioisotope to decay |
| transmutation | conversion of atoms of one element to another type of element |
| transuranium elements | elements after uranium on the periodic table |
| quark | subatomic particle theorized to be the basis of matter |
| strong nuclear force | attractive force that binds protons and neutons together in the nucleus |
| fission | splitting of an atomic nucleus into two smaller parts |
| chain reaction | neutrons released during the splitting of an initial nucleus trigger a series of nuclear fissions |
| critical mass | smallest possible mass of a fissionable material that can sustain a chain reaction |
| plasma | a state of matter in which atoms have been stripped of their electrons |
| fusion | a process in which the nuceli of two atoms combine to from a larger nucleus |
