Across
- 2. you need 2 to have a water molecule
- 6. it make thyroid hormones
- 9. 7 neutrons
- 12. it is necessary for the growth of bones
- 14. a gas
- 17. you use this to wrap some food
- 18. 5 cents
- 20. it can harm the body
Down
- 1. mass of 20 amus
- 3. Pb symbol
- 4. it regulates the earth´s temperature
- 5. it is necessary for plants to grow
- 7. it helps fix and build DNA
- 8. 78 neutrons
- 10. it has 14 electrons
- 11. it helps maintain blood pressure
- 13. you breath this to live
- 15. a lot of people use this as money
- 16. it helps muscles contract
- 19. you use this to inflate balloons