Across
- 5. a model with negatively charged electrons scattered about
- 9. a revolutionary physicist who used Heisenberg’s uncertainty principle to come up with the atomic model that is used today
- 12. a physicist who is credited for discovering the electron
- 15. the first to adapt Democritus theory into the first modern atomic model
- 17. the average mass of the atom, with the isotopes
- 19. that the position and the velocity of an object cannot both be measured exactly at the same time
- 21. subatomic particle located in the nucleus with no charge
- 22. this model shows the protons and neutrons located inside the nucleus, and the electrons distributed around the nucleus
Down
- 1. dalton thought atoms were the smallest particles of matter, so he envisioned them as spheres and made this model out of the information he discovered
- 2. a model that required electrons to move in orbits of fixed size and energy
- 3. the first person to use the term atom
- 4. a model that treats electrons as matter waves
- 6. subatomic particle located in the nucleus with a positive charge
- 7. he observed that the electrons have almost no mass
- 8. discovered that there was a smallest unit charge, or a charge that is quantized
- 10. the number of protons and neutrons
- 11. he set up his now famous Gold Foil Experiment
- 13. subatomic particle located in the electron cloud with a negative charge
- 14. a piece of equipment Thomson used to study the nature of electric discharges
- 16. dalton formed this theory to determine the components and rules of atoms
- 18. he was able to answer why the electrons did not collapse into the nucleus
- 20. created the definition of an element: any substance that cannot be decomposed into a simpler substance