| A | B |
| physical change | Ice melting and freezing |
| chemical change | rust forming on iron |
| salad dressing separating over time | physical change |
| A Magnesium strip ignites when exposed to heat and oxygen | chemical property |
| Calcium | Reactive metal |
| unreative metal | Zinc |
| Halogens | Group 17 (7A), unreactive nonmetals |
| Group 18 (8A) | Noble Gases |
| Horizontal row | period |
| Group | veritcal column |
| Alkali metals | Group 1, very reactive metals |
| Shares properties with both metals and nonmetals | metalloids |
| The number of valence electrons in an atom of Se | 6 |
| 2 | The number of valence electrons in an atom of Ga |
| The number of protons in an atom of Boron | 5 |