1. Models of the Atom

2. 1904 – JJ Thomson’s Model
Plum Pudding Model (or Chocolate Chip Cookie Model)
His Theory: The majority of the atom is positively charged, and the electrons are embedded in the positive “core”.

3. Plum Pudding
Model
2 Dimensional
Generic Model

4. Cathode ray – Thomson’s experiment that was used to support the idea of electrons. The negatively charged electrons were deflected toward the positive end of the magnet.

5. 1911 – Rutherford’s Model His Theory: He identified the
nucleus and said that it
was positively charged.
He also said that the
electrons were randomly
placed around the outside
of the nucleus

7. 1913 – Bohr’s Model
His Theory – He added to Rutherford’s model by including neutrons in the nucleus as well as stating that the electrons were traveling in fixed orbits around the nucleus (like planets around the sun)

8. 1928 – Electron Cloud Model
This model is the currently accepted model.
EXTREMELY small, heavy nucleus that contains the protons and neutrons
Electrons are very small and light and they travel around the nucleus randomly within energy levels but not in a fixed path

9. Bohr’s Electron
Model Cloud Model

10. Move in space around the nucleus
Atom Anatomy
Charge
Location
PROTONS
Positive
Nucleus
NEUTRONS
Neutral
ELECTRONS
Negative
Move in space around the nucleus

11. Sizes of subatomic particles
Protons and neutrons are about 10,000 times bigger than electrons

12. SIZE OF ATOMS
If you draw an line across the diameter of a penny, there are 810,000,000 atoms of Copper