1. Development of the Atomic Model

2. 400 B.C. – Democritus He thought atoms were “un-cuttable” Also atoms are hard small particles

3. 1808-Dalton He believed that all substances are made of atoms. Atoms of the same element are exactly alike, and with different elements are different. He made experiments in combining elements.

4. 1897-Thomson The atomic structure was led to the plum- pudding model. Discovered the electron He made a cathode-ray tube experiment

5. 1911-Rutherford The electrons move in empty space in the atom Discovered the nucleus Performed the gold foil experiment Inside are small negatively changed particles in a atom

6. 1913-Bohr Electrons travel in definite paths; orbit the nucleus The electrons jump from path to path.

7. 1926-Schrodinger The electrons path cannot be predicted The electrons are found in the electron cloud not paths

8. Word reminder Democritus- snowflake or popcorn. Dalton-ball Thomson-chocolate chip cookie Rutherford- sprinkle doughnut Bohr- plants Schrodinger-electron cloud

9. 1)Who believed that the electrons were found in electron cloud ? 2) Who thought that jump from path to path? 1)A) Bohr B) Schrodinger C) Rutherford D) Thomson 2) A) Bohr B) Dalton C) Democritus D) Rutherford

10. 1)Who believed that atoms are “uncuttable”? 2)Who believed that atoms of the same element are exactly alike? 1) a) Dalton b) Democritus c) Thomson d) Bohr 2) a ) Dalton b ) Bohr c ) Rutherford d ) no clue.

11. Thomson conducted what experiment? A) Experiment in combining elements. B) Gold foil experiment C) Cathode-ray tube D) Electron clouds

12. THE END (: