Across
- 3. a column
- 4. something new
- 6. reactivity
- 7. physical substance
- 9. substance that isn't metal
- 12. something that can't be divided any more
- 13. not reactive
- 15. inbetween metal and nonmetal
- 18. around nucleus
- 20. chart of elements
Down
- 1. protons and neutrons
- 2. the outer shell
- 5. neutral
- 8. A=P=E
- 10. positive electrical charge
- 11. negative charge
- 14. mass number-atomic number=neutrons
- 16. same charge pushes each other away
- 17. a row
- 19. center