1. Announcements Tests are not graded  Turn labs into basket
Mole Party, Mon 10/23 – BRING FOOD!
Dates:
Stoichiometry Grade Recovery (Friday 10/27)
ALL MAKEUP WORK DUE FRIDAY 10/27

2. What does an atom look like?
You all have a sticky note at your seat
Think for a few seconds about an atom
Draw what you best believe an atom to look like (there is no right or wrong here, just do your best)
Stick it on the paper when you finish

3. History of the Atom

4. Democritus Around 400 B.C. Atomos  indivisible
He suggested that all substances in the universe were made up of particles so minute that nothing smaller was possible
He regarded those particles as unchangeable and indestructible, and as the only content of the universe

5. The “Mocker”

6. Dalton 1803 Atoms = small, dense, spheres Billiard Ball Model
Atomic Theory

7. Dalton’s Atomic Theory
All matter is composed of tiny particles called atoms
Atoms of the same element are identical
Compounds are made with whole number ratios of atoms
Atoms are indivisible
Chemical reactions occur when atoms are rearranged. The atoms are not changed

8. Thomson 1897 Discovered the electron, and they were negative
Cathode Ray Tube experiment
Plum pudding model

9. Rutherford 1911 Gold Foil Experiment
Discovered atom was mostly empty space
Discovered the nucleus
Dense, positive, small, in center
Atomic Model

10. Bohr 1913 Electrons were located in shells (fixed orbits)
Electrons can move to other shells
Planetary Model

11. Millikan 1916 Oil-drop experiment Mass of an electron
Exact charge of an electron

12. Schrödinger 1926 Electron cloud of probability
Heisenberg Uncertainty Principle
Electron Cloud Model (Modern Model)

13. Chadwick
1932
Discovered the neutron

14. History of the Atom

15. Models of the Atom
Use textbook pg. 128 or internet (just make sure the model you find is accurate)
Each square should be neat and have color
Dalton
Year
Model (drawn & labeled)
Significance
Thomson
Year
Model (drawn & labeled)
Significance
Rutherford
Year
Model (drawn & labeled)
Significance
Bohr
Year
Model (drawn & labeled)
Significance