Across
- 3. Chemical symbol with valence electrons
- 6. Electrons in the outer energy level.
- 7. Vertical columns on the periodic table.
- 11. Equal to the number of protons and neutrons.
- 12. Same # of protons but different # of neutrons.
- 13. Well defined areas in which electrons orbit.
Down
- 1. Equal to the number of protons or electrons
- 2. Weighted mass of all the isotopes
- 3. Negatively charged subatomic particle of an atom
- 4. Positively charged subatomic particle of an atom.
- 5. Neutrally charged subatomic particle of an atom.
- 8. Horizontal rows on the periodic table.
- 9. Energy levels with all of the electrons.
- 10. Center part of an atom that contains all the mass