| A | B |
|---|
| Alkali Metals | Group 1A extremely reactive metals. |
| Alkaline Earth Metals | Group 2A harder and stronger metals that react to water |
| Atomic Mass Units | One twelfth the mass of a carbon atom. |
| Groups | Each column in the periodic table. |
| Halogens | Group 7A extremely reactive nonmetals |
| Metalloids | Elements with properties in between metals and nonmetals. |
| Metals | Good conductors of heat and electric current. |
| Noble Gases | Group 8A, non-reactive |
| Nonmetals | Poor conductors of heat and electric current. |
| Period | Each row in the periodic table. |
| Periodic Law | Repeating pattern of properties on the periodic table. |
| Transition Metals | Metals in the middle of the periodic table. |
| Valance Electrons | Electrons in the highest orbital |
| Mendeleev | Father of the periodic table |
