Across
- 3. Group 7A on the periodic table
- 5. Can be found in quartz crystal, sand, and glass
- 6. Added to toothpaste and drinking water to protect tooth enamel from decay
- 8. The designer of the periodic table of elements
- 9. _______ number indicates the valance electrons
Down
- 1. Found widely in nature- rocks, coral reefs
- 2. Most abundant metal in earth’s crust
- 4. Indicates the number of energy levels
- 5. The number of non metal elements on the periodic table of elements
- 7. Used in blimps, airships, and balloons