Across
- 3. positively charged ion
- 5. the center of an atom
- 8. composed of two or more elements NOT chemically combined
- 9. made of one or more atoms
- 11. starting substance in a chemical reaction
- 12. negatively charged ion
- 14. name of first group elements
- 15. gold foil experiment director
- 17. primary chemistry unit
- 18. the outermost shell of electrons
- 19. positively charged particle
- 20. the smallest particle of an element
- 22. total electrons in outer shell
- 23. 12C and 13C
- 25. change that produces a new substance
- 27. repeating trends in elements properties
Down
- 1. substance made during a chemical reaction
- 2. reversible type of change
- 4. composed of two or more elements chemically combined
- 6. a chemical substance that cannot be broken down
- 7. tendency to attract electrons
- 10. bond with shared electrons
- 13. nonreactive gases
- 16. developed an early model of the atom
- 21. negatively charged particle
- 24. elements bonded with themselves, O2
- 26. group having seven valence electrons