Across
- 4. Protons and electrons
- 6. negatively charged particles
- 9. atomic mass unit
- 11. vertical columns
- 12. horizontal rows
Down
- 1. Christmas pudding
- 2. Father of nuclear physics
- 3. center of atom
- 5. sphere positive charge
- 7. neils bohr
- 8. smallest building block
- 10. goldfoil