Across
- 3. one or more elements combined
- 5. in nucleus of an atom, positive charge
- 6. same number of electrons and protons
- 7. substance that undergoes a chemical change
- 8. space outside the nucleus of an atom
- 9. two different elements combined
- 10. created periodic table
- 11. atomic number increases from left to right
- 12. outer most orbital
- 15. mass of atom in an element
- 18. column of elements
- 20. the smallest form of matter
- 21. energy observed making reaction cooler
- 23. regarded as representing something
Down
- 1. layer of metal is bonded to the surface of another substance
- 2. mix between non metals and metals
- 4. principale that matter cannot be created or destroyed
- 5. substance obtained from another substance through chemical change
- 13. poor conducter of both heat and electricity
- 14. substance that can't be chemically broken down
- 16. energy released in the form of heat
- 17. no charge
- 19. gaseous element group 8a or 0
- 22. positively charged in center of an atom
- 24. substance in its pure state