1. Atomic Theory
Means there is a link on the page. Click on the image

2. John Dalton (1800) Pure elements consist of atoms.
Atoms of an element are all the same for that element. (all gold atoms are the exact same)
Atoms can be told apart by their atomic weights.
Atoms unite to form chemical compounds.
Atoms can neither be created or destroyed in chemical reaction.

3. J.J. Thomson (1850) Cathode Ray Tube Experiment
Discovered negatively electrons
Plum pudding model

4. Ernest Rutherford (1905) Gold foil experiment Discovered that:
Atoms are mostly empty space
Atoms have a nucleus (positively charged)
Electrons move around nucleus at distance
Nuclear atom model

5. Niels Bohr (1920) Electromagnetic Spectrum
the entire spectrum, considered as a continuum, of all kinds of electric, magnetic, and visible radiation

6. Waves Wavelength: distance from crest to crest
Short wavelengths = higher energy
Amplitude: distance from level of crest to level of trough
wavelength
amplitude

7. Waves Frequency: number of crest passages per unit time
Higher frequency = higher energy

8. Electromagnetic Spectrum
ROYGBV

9. Invisibility Cloak Infrared waves Object

10. Niels Bohr (1920) Studied energy emissions from hydrogen
Continuous spectrum: all visible light waves present
versus
Bright line spectrum: certain (discrete number of) visible light waves present

11. Niels Bohr (1920) Studied energy emissions from hydrogen
Electrons can only exist on definite energy levels that are specific distances from the nucleus.
Planetary model
Draw arrows of energy

12. Current Model of Atom

13. Quantum Mechanical Model
Mathematical model
The model estimates the probability of finding an electron in a certain position
Denser area =
higher chance of finding an electron