chemistry extra credit!

1234567891011121314151617
Across
  1. 3. same number of valence electrons
  2. 7. opposite of proton
  3. 8. opposite of electron
  4. 11. this number is
  5. 12. mark, sign, or word that indicates something chemistry identifies substances matter is composed similar alike
  6. 13. hard, shiny, malleable, fusible,
  7. 14. neutral atom
  8. 15. substance that expands freely
  9. 16. " ******** table"
  10. 17. how heavy
Down
  1. 1. elements with similar properties
  2. 2. determines the number of atoms combined
  3. 4. smallest unit of matter
  4. 5. same number of electron shells
  5. 6. between those of metals and nonmetals
  6. 9. showing high moral principles and ideals.
  7. 10. a pure substance consisting of atoms
  8. 14. an element or substance that is not a metal.