Across
- 3. mixed with chlorine to make salt
- 4. Makes your bones strong
- 7. number 14 on the periodic table
- 9. used to clean water
- 11. used in cryogenic refrigerant
- 12. main fuel for space shuttle
- 16. used in fireworks
- 18. cleaning agent used in toothpaste
- 19. used for batteries
Down
- 1. used to make fertilizers
- 2. Banana
- 4. used to make strongly bonded chains
- 5. used in soda cans
- 6. used to make boric acid
- 8. 78 percent of this makes up the atmosphere
- 10. we breathe this stuff
- 13. alloying agent for copper
- 14. used in gunpowder
- 15. used to make balloons float
- 17. protective shield in arc welding