whodunit

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Across
  1. 1. Positively charged ion
  2. 3. Substance made during a chemical reaction
  3. 7. Group having seven valence electrons
  4. 10. Bond with shared electrons
  5. 12. 13C and 12C
  6. 14. The smallest particle of an element
  7. 16. The ability of a material to be stretched into a long wire
  8. 17. These have properties of both metals and nonmetals
  9. 20. Starting substance in a chemical reaction
  10. 22. A liquid's resistance to flow
  11. 24. Nonreactive gases
  12. 25. Tendency to attract electrons
Down
  1. 2. The center of an atom
  2. 4. Repeating trends in elements properties
  3. 5. Elements bonded with themselves, O2
  4. 6. Gold foil experiment director
  5. 8. Positively charged subatomic particles
  6. 9. Developed an early model of the atom
  7. 11. A substance whose atoms all have the same number of protons
  8. 13. Negatively charged subatomic particle
  9. 15. Mass per volume of a substance
  10. 18. Name of first group elements
  11. 19. Has a pH less than 7
  12. 21. Negatively charged ion
  13. 23. The outermost shell of electrons