Across
- 1. - Gold Foil Experiment that discovered the atomic nucleus
- 5. - A negatively charged ion (has gained electrons)
- 6. - The small, dense, positively charged center of an atom
- 8. Mass Unit (amu) - Unit of mass equal to 1/12 the mass of a carbon-12 atom
- 11. Mass - The weighted average mass of all naturally occurring isotopes of an element
- 13. - Atoms of the same element with different numbers of neutrons
- 15. - created Plum Pudding Model of the atom with electrons embedded in a sphere of positive charge
- 16. - An atom or group of atoms with a net electrical charge
- 18. - Greek word meaning "indivisible"
- 19. - The smallest unit of matter that retains the properties of an element
Down
- 2. - created the Uncertainty Principal States that position and momentum of an electron cannot both be known precisely
- 3. - Neutral particle (no charge) located in the nucleus
- 4. - The Mechanical Model describing electrons as existing in probability clouds
- 5. Number (Z) - The number of protons in an atom's nucleus
- 7. - (Particles) smaller than an atom (protons, neutrons, electrons)
- 9. - A positively charged ion (has lost electrons)
- 10. - Negatively charged particle orbiting the nucleus
- 12. - Positively charged particle located in the nucleus
- 14. - A region of space where electrons are most likely to be found
- 17. Number (A) - The sum of protons and neutrons in the nucleus