| A | B |
|---|
| Group | also a family, vertical row |
| Period | horizontal row |
| Metals | On left of Periodic Table |
| Nonmetals | On right of Periodic Table |
| Metaloids | Along the stairsteps |
| Alkali Metals | Very Active due to 1 valence electron. |
| Alkaline Earth Metals | Commonly found in the Earth. Active |
| Transition elements | Metals, slightly active with 2 val. elec. |
| Actinide Series | Radioactive synthetic elements |
| Lathanide Series | Has 1 or 2 valence electrons, semi-active metals |
| Boron Family | 3 Val. elec. semi-active, give up, take or share electrons |
| Carbon Family | 4 Val. elec, slightly active |
| Nitrogen Family | 5 Val. elec, active, take or share electrons. |
| Oxygen Family | very active, 6 elec. take or share electrons |
| Halogen Family | 7 val. elec., very active - take or share an electron |
| Nobel Gases | Valence shell full - very stable |
| Mendeleev | Arranged elements by atomic mass |
| Mosley | Arranged elements by atomic number |
| Atomic number | tells number of protons and electrons |
| valence electrons | The electrons in the outer shell of the Bohr model. |
