Across
- 3. number protons + electrons
- 4. negatively charged particles in energy levels
- 6. discovered all matter is composed of atoms
- 10. discovered a positively charged nucleus with protons inside
- 11. discovered electrons
Down
- 1. discovered electrons orbit in energy levels
- 2. electrons electrons on the outermost ring
- 5. neutral charge particles in nucleus
- 7. are positively charged particles located in nucleus
- 8. number same as the number of protons and electrons
- 9. atoms of the same element that have a different number of neutrons and mass