Across
- 2. is total number of protons and neutrons in a atom
- 7. if an atom loses a electron then it becomes
- 8. have a positive charge
- 10. very reactive nonmetals
- 13. are rare earth elements
- 18. atoms produce energy and heat
- 20. the number of protons changes
- 22. when a electron is added
- 23. has no charge
- 24. element that conducts electricity and heat
- 25. the center of a atom
Down
- 1. less reactive earth metals
- 3. gas that never reacts with other elements
- 4. in rows on the periodic table
- 5. found in column
- 6. have properties of both metals and nonmetals
- 9. are very reactive
- 11. tell you how many protons a atom has
- 12. has a negative charge
- 14. shows all place that electrons would be
- 15. a series with 15 elements
- 16. same element but different mass
- 17. is the opposite of metal
- 19. same element but different number of electrons
- 21. generally less reactive