Across
- 5. they share.
- 9. The 18 vertical (up/down) columns of elements in the periodic table.
- 10. The building blocks of matter.
- 11. A negatively charged particle.
- 12. The 7 horizontal (across) rows of elements in the periodic table.
Down
- 1. The combined number of protons and neutrons found in the
- 2. A neutrally charged particle.
- 3. The smallest form of matter
- 4. A positively charged particle.
- 6. The number of protons found in an atom's nucleus.
- 7. A tool used by chemists to help arrange the elements based on certain
- 8. The positively charged center of an atom that contains protons and neutrons.