| A | B |
|---|
| triad | a group of three elements with similar properties |
| law of octaves | same properties that appear every 8 element when the elements are listed in order of thier atomic masses |
| periodic table | pictorial arrangement of the elements based upon thier atomic numbers and electron configurations |
| transition element | element whose highest energy electron is in a d sublevel |
| lanthanoid series | 14 elements beginning with lanthanum in which the arrow diagram predicts the highest energy electrons to be in the 4f sublevel |
| actinoid series | 14 elements beginning with actinium in which the arrow diagram predicts the highest energy electrons to be in the 5f sublevel |
| period | horizontal row of the periodic table |
| group | elements of a vertical column of the periodic table |
| octet rule | the tendency of atoms to gain or lose electrons so that they aquire 8 electrons in thier outer level |
| family | elements composing a vertical column of the periodic table |
| metal | an element that tends to lose electrons in chemical reactions |
| nonmetal | element that tends to gain electrons in chemical reactions |
| metalloid | element that has properties characteristic of a metal and a nonmetal |
