Across
- 3. mass number-atomic mass
- 7. H2O
- 10. mixtures
- 12. workplace hazardous materials information system
- 13. a table of chemical elements
- 14. air combine with metal
- 15. oxygen combines with a substance
- 16. reaction
- 18. burning
- 19. physical substance
Down
- 1. organic catalysts
- 2. groups
- 4. releases heat energy
- 5. mass
- 6. absorbs heat
- 8. charged atom
- 9. period
- 11. fire
- 17. shinny