Across
- 2. What salt is composed of
- 4. For formation of bones and teeth
- 6. What some pools have
- 8. Atomic number of 4
- 9. Has an atomic number of six
- 13. Symbol is Al
- 14. Used in lamps and signs
- 17. flammable gas
- 18. symbol is Ar
- 19. what we put in balloons so they can go up
- 20. Atomic number is 9
Down
- 1. something that is important in body functions
- 3. Milk has this
- 5. Used to make glue
- 7. a soft silver white metal
- 10. Makes up 78 percent of the earths atmosphere
- 11. Has 2 valence electrons
- 12. Atomic number of 16
- 15. What we breathe
- 16. Has 2,3 electrons per shell