| A | B |
|---|
| triad | a group of three elements with similar properties |
| law of octaves | the same properties appear every eighth element when the elements are listed in order of their atomic masses |
| periodic law | the properties of the elements are a periodic function of their atomic numbers |
| periodic table | a pictorial arrangement of the elements based upon their atomic numbers and electron configurations |
| transition element | an element whose highest energy electron is in a d sublevel |
| lanthanoid series | fourteen elements beginning with lanthanum in which the arrow diagram predicts the highest energy electrons to be in the 4f sublevel |
| actinoid series | fourteen elements beginning with actinium in which the arrow diagram predicts the highest energy electrons to be in the 5f sublevel |
| period | a horizontal row of the periodic table |
| group | the elements of a vertical column in the periodic table |
| octet rule | the tendency of atoms to gain or lose electrons so that they acquire eight electrons in their outer level |
| family | the elements composing a vertical column of the periodic table |
| metal | an element that tends to lose electrons in chemical reactions |
| nonmetal | an element that tends to gain electrons in chemical reactions |
| metalloid | an element that has properties characteristic of a metal and a nonmetal |
| hydrogen ion | a hydrogen atom that has lost its electron; H+;a proton |
| hydride ion | a hydrogne atom that has gained an electron; H- |
| catalyst | a substance that speeds a chemical reaction without being permanently changed itself |
| carbide ion | a carbon atom that has gained four electrons; C-4 |
| organic compound | a compound containing carbon, with a very few exceptions |
| catenation | the joining of like atoms in chains |
| inorganic compound | a molecular compound that does not contain carbon |
| allotrope | form of an element differing in crystal or molecular structure |
| silicate | compound containing silicon and oxygen |
| amphoteric | having the ability to act as either an acid or base |
| galvanizing | coating iron with a protective layer of zinc |
| inner transition element | those elements that fall between numbers 57 and 70 and between numbers 89 and 102 of the periodic table |
