Across
- 3. The horizontal lines on the periodic table.
- 5. The two most reactive groups.
- 11. The mass of an atom.
- 12. Make up the right side of the periodic table.
- 13. Are on a zigzag line in the periodic table.
Down
- 1. The number of electrons on the outermost ring in the electron cloud.
- 2. The vertical lines on the periodic table that determine reactivity.
- 4. They are positively charged subatomic particles.
- 6. The least reactive group, also known as the noble gasses.
- 7. They are neutrally charged subatomic particles.
- 8. Make up the left side of the periodic table.
- 9. They are negatively charged subatomic particles.
- 10. The number of protons in an atom.