Across
- 1. negatively charged atoms
- 3. negatively charged
- 6. he said that the atom was like a plum pudding
- 8. vertical columns on the periodic table
- 11. horizontal columns on the periodic table
- 12. positively charged atom
- 15. pure substance
- 16. he did the gold foil experiment
- 18. positively charged
- 19. the outer shell
- 20. he proposed the idea of electron shells
Down
- 1. a particle made of protons, neutrons,electrons
- 2. contains protons and neutrons
- 4. positively charged or negatively charged atom
- 5. combination of different elements
- 7. a place where electrons orbit the nucleus
- 9. proton
- 10. H2O
- 13. no charge
- 14. electron
- 17. he said that elements form in simple ratios