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 |