Across
- 2. This person discovered energy levels
- 4. This person discovered the nucleus
- 6. What you get when you add the neutrons and protons
- 10. How many protons are in a nucleus
- 11. A ______has a neutral charge
- 12. An abbreviation of an element
- 13. A ______ has a negative charge
- 14. An electron has a _______ charge
- 15. A ______ has a positive charge
Down
- 1. This person has the most developed theory of atoms
- 3. The _____ is where the protons and neutrons are located
- 5. A theory of the nature of matter
- 7. This person discovered that atoms contain negatively charge particles
- 8. The protons, neutrons, and electrons are located inside of the...
- 9. This person developed the electron cloud model