| A | B |
|---|
| Actinide | Elements found in the second series of the inner transition elements. |
| Group | The elements in the vertical columns of the periodic table |
| Lanthanide | Elements found on the first series of the innier tansition elements |
| MEtal | An element that has luster (shine), conducts electricity and heat, and usually bends without breaking |
| Metalloid | An element with some physical and chemical properties of metals and other properties of nonmetals |
| Noble gas | An element that has a full set of valence electrons and therefore it is unreactive |
| Nonmetal | An element that in general does not conduct electricity, is a poor conductor of heat, and is brittle when solid. |
| Period | A horizontal row in the periodic table |
| Periodic Law | The physical and chemical properties of the elements repeat in a regular pattern when they are arranged in order of increasing atomic numbers |
| Periodicity | The tendency to occur at regular intervals. |
| Semiconductor | An element that does not conduct electricity as well as a metal, but that does conduct slightly better than a nonmetal |
| Transition element | An example would be iron. |
