| A | B |
|---|
| atomic number | number of protons (the only charged particles in the nucleus) |
| atomic mass unit | proton and neutron masses |
| mass number | number of neutrons and protons |
| nuclide | the nucleus of an isotope |
| strong nuclear force | force that acts between protons and neutrons tha are close together |
| nucleon | both protons and neutrons |
| binding energy | difference between the energy of the assembled nucleus and the energy of the separate protons and neutrons |
| mass defect | difference between the sum of the masses of the individual nucleons and the actual mass |
| radioactive | describes material that emits radiation |
| alpha decay | the emission of an elpha particle from a nucleus |
| beta decay | occurs when a neutron is charged to a proton within the nucleus |
| gamma decay | results from the redistribution of energy within the nucleus |
| nuclear reaction | occurs whenever the energy or number of neutrons or protons in a nucleus changes |
| half life | time required for half of the atoms in any given quantity of a radioactive isotope to decay |
| fission | division of a nucleus into two or more fragments |
| chain reaction | continual process of repeated fission reactions |
| fusion | nuclei with small masses combine to form a nucleus with a larger mass. |
