The Atom and Periodic Table

1234567891011121314151617
Across
  1. 3. Atomic mass of about 207 amu
  2. 7. Atomic number 8
  3. 8. Contains 22 electrons
  4. 10. Created the first periodic table based on atomic mass
  5. 14. Protons plus neutrons; atomic ________
  6. 15. Atomic mass of 20
  7. 16. First element on the periodic table
  8. 17. Contains both protons and neutrons
Down
  1. 1. Element symbol Au
  2. 2. contains 87 electrons
  3. 4. Group #17 on the periodic table
  4. 5. Negatively charged subatomic particle
  5. 6. Created the modern periodic table based on atomic number
  6. 8. Atomic mass of about 119 amu
  7. 9. 86 protons
  8. 11. The number of protons an element has; atomic _________
  9. 12. Positively charged subatomic particle
  10. 13. Element symbol Y