Across
- 2. negatively charged particle
- 4. the table that contains an arrangement of all known elements
- 6. number of protons and electrons
- 9. average mass of all isotopes of that element
- 12. particle with no charge
- 13. diagram mental picture mathematical statement or an object that helps explain a concept
Down
- 1. one or two letter abbreviation for each element
- 3. very small center core of an atom
- 5. positive charged particle
- 7. sum of the protons and neutrons
- 8. the smallest unit of matter
- 10. horizontal rows in the periodic table
- 11. vertical columns in the periodic table
- 13. makes up everything in the universe