Across
- 3. Gass element
- 5. thing to organize
- 6. Russian chemist; helped make periodic law
- 9. Number of positive charges
- 10. not separated
- 11. thing to separate
- 12. amount of content
Down
- 1. abbreviations of element
- 2. electrons
- 4. cold
- 7. rule
- 8. Warm