Across
- 3. the column vertical
- 5. are tiny particles that make up matter
- 7. numbers of protons but different numbers of neutrons in their nuclei
- 9. is neutral
- 12. protons
- 14. electron
- 16. made the gold foil experiment
- 17. made the plum pudding model
- 19. a positively charged ion
Down
- 1. H2O
- 2. the column horizontal
- 4. made up the atomic theory
- 6. is positively charged
- 8. a pure substance
- 10. is the center part composed of protons and neutrons
- 11. are made up of two or more different elements
- 13. is a atom or molecule with a net electric charge due to the loss or gain of one or more electrons
- 15. is negatively charged
- 18. it holds electrons
- 20. a negatively charged ion