2. Big Ideas Structure & Properties of Matter
The nature of the attractive forces that exist between particles in a substance determines the properties, and limits the uses of that substance
Technological devices that are based on the principles of atomic and molecular structures can have societal benefits and costs

3. Atomic Theory
the theory that all matter is made up of tiny indivisible atoms
atoms of each element are effectively identical, but differ from those of other elements, and unite to form compounds in fixed proportions

4. The Atomic Model What does an atom look like?
The answer to this question has evolved over many years…

5. Democritus 460 BCE – 370 BCE
Ancient Greek philosopher who proposed that if an object was cut-in-half over and over again, eventually you reach a point at which it could not be cut-in-half anymore
This piece was said to be indivisible or (ἄτομος; “atomos”)

6. John Dalton 1803 Matter divided into small, indivisible atoms
Each elements made of different atoms

7. Dalton’s Billiard Ball Model

8. JJ Thomson 1897 discovered positive/negative charges within atom
Cathode Ray Tube Experiment:

9. JJ Thomson’s Raisin Bun Model

10. Ernest Rutherford 1911
-discovered negative electron cloud surrounding central, positively charged nucleus
Gold Foil Experiment

11. Rutherford’s Beehive Model

12. Niels Bohr 1913
-described surrounding electrons to be locked into “orbits” of specific energy levels 

13. Bohr’s Solar System Model

14. Quantum Mechanics
17 of the 29 attendees were, or became, Nobel Prize Winners

15. Quantum Mechanical Model
It turns out, that all those models were incomplete
This is where the electrons really are… 

16. Quanta – plural Quantum – singular
Atoms & electrons, cannot be seen, only modelled
They are modelled by the way that they respond to energy (electormagnetic) input
Energy is given to the particles (atoms/electrons etc) and the response is detected
Hypotheses are formulated which are then tested by all available means
If the experimental evidence seems to fit the hypothesis then a theory is proposed which in time comes to be accepted as the "truth“ or the “accepted model”

17. The Photon
1873: James Maxwell proposes that light is an electromagnetic wave that can exert forces on charged particles.
Earlier scientists including Isaac Newton felt that light should be studied as particles
1887: Heinrich Hertz discovers the photoelectric effect

19. Bohr & Hydrogen Bohr excited electrons with light (photons)