Across
- 3. molecules stay in place
- 5. neutrally charged
- 7. developed the Bohr model of an atom
- 8. the number of protons
- 11. protons and neutrons stay here
- 13. a table of the chemical elements arranged in order of atomic number
- 15. the basic unit of a chemical element.
- 16. a group of atoms bonded together
- 19. the mass per unit volume of a substance
Down
- 1. negatively charged
- 2. positively charged
- 4. the mass of an atom
- 6. a thing that is composed of two or more separate elements
- 9. atomic weight
- 10. atomic orbital
- 12. formed the Periodic Law
- 14. Molecules are spread far apart
- 17. molecules pass through each other
- 18. pure substance