Across
- 2. 6th element, backbone of life
- 4. Second row from the left of the periodic table
- 6. Common element, found in table salt
- 9. Negatively charged subatomic particle
- 12. Elements 57-71, separate from the table
- 13. Used to detect pH
- 14. Elements touching the "stair-step"
- 16. OH-, very strong base
- 17. Toxic gas at room temp, found in table salt
- 19. Low pH
- 20. Lightest of the most reactive elements
Down
- 1. Vertical column on the periodic table
- 3. Solid falls out of solution in a reaction
- 5. Positively charged subatomic particle
- 7. Horizontal row on the periodic table
- 8. Hg, a very toxic element
- 10. Changing the substance's identity
- 11. Type of compound with 2 elements
- 15. Ion with more than one element
- 18. Center of the atom