2. Small individual particles that make up matter. This includes gases

3. Can be broken into three subatomic particles

4. Electrons – negatively charged particles outside of the nucleus Protons – positively charged particles in the nucleus Neutrons – neutrally charged particles in the nucleus https://www.youtube.com/watch?v=_IVqMXPF YwI

5. Developed first atomic theory All matter is made of atoms which are tiny indivisible particles The word atom comes from the Greek word “atomos” which means indivisible

6. Considered the father of atomic theory Set the foundation for the current atomic theory Proposed that: 1. All matter consists of tiny particles called atoms 2. Atoms are indestructible and unchangeable 3. Elements are characterized by the weight of their atoms 4. Atoms combine in small, whole number ratios 5. Atoms may combine in more than one whole number ratio

7. Used cathode ray tube to determine that electrons have mass and are negatively charged Developed Plum Pudding Model

9. Electrons were positioned in a “pudding” that had a positive charge

10. Discovered the nucleus of an atom using his gold foil experiment Discovered protons and found them to be in the center of the atom Determined that the atom was mostly empty space

12. Electrons exist in specific orbits outside of the nucleus. This is called the planetary model Electrons cannot exist in-between levels

13. Developed the quantum mechanical model Used mathematical equations to predict location of electrons Electrons do not have direct paths that they travel in but exist in clouds outside of the nucleus

16. The advancement of technology has played the biggest influence in the atomic model As technology increases, our understanding of the world increases https://www.youtube.com/watch?v=oSCX78-8-q0 https://www.youtube.com/watch?v=xA4QWwaweWA&feature=iv&src _vid=oSCX78-8-q0&annotation_id=annotation_743526523