Periodic Table Crossword

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Across
  1. 6. The number of protons in the nucleus of an atom
  2. 9. The SI fundamental unit for "amount of substance."
  3. 10. A value indicating the distance that an electron may move away from the nucleus of anatom
  4. 13. The center of an atom, a region where protons and neutrons are located
  5. 14. smallest particle of an element that retains all the chemical and physical properties of the element
  6. 16. A subatomic particle that has no electric charge
  7. 17. A pattern of probabilities regarding the regions that an electron can occupy within an atom in a particular energy state
  8. 19. An atom or atoms that has lost or gained one or more electrons
  9. 20. The length of time it takes a substance to diminish to one-half its initialamount
Down
  1. 1. Electrons that occupy the highest energy levels in anatom
  2. 2. Another term for chemical symbol
  3. 3. Atoms that have an equal number of protons
  4. 4. A positively charged particle in an atom
  5. 5. Columns on the periodic table of elements
  6. 7. A substance made of two or more elements that have bonded chemically
  7. 8. Rows of the periodic table of elements
  8. 11. The center of an atom, a region where protons and neutrons are located
  9. 12. A negatively charged particle in an atom
  10. 15. A group of atoms,usually but not always representing more than one element
  11. 18. A substance made up of only one kind of atom, which cannot be chemically broken into other substances