1. The Structure of the Atom
Bohr, Energy Levels and Elementary Particles

2. Review In your groups, review from last class:
what are the 3 subatomic particles we’ve learned about?
what subatomic particle determines the identity of the element?
what subatomic particle has a positive charge?
what subatomic particle has a negative charge?
what subatomic particle has a neutral charge?
how do you determine the mass of an atom?

3. Topics for Today Bohr and orbitals atomic number and atomic mass
Strong nuclear force (and mesons)
Elementary particles
quarks
gluons
leptons
mesons

5. Bohr Atomic Model of an Atom
electron orbitals or “energy levels”
electron
proton
neutron
electrons can jump from one energy level to another but cannot exist in between

6. Let’s Compare Models…
On a whiteboard, draw a Venn diagram of the similarities & differences between the Rutherford Model & Bohr Model
Rutherford
Bohr
Both

8. Protons
Neutrons
Electrons

11. (one quark and one “anti-quark”)

12. Protons and Neutrons are made of “Up” and “Down” Quarks

13. Proton
Neutron
Each Quark has a “partial charge” that is either + or –
“Up” quarks have a charge of +2/3
“Down” quarks have a charge of -1/3

14. Proton
+2/3
-1/3
= + 1
Neutron
+2/3
-1/3
= 0

17. Mesons
Quarks
Gluons
Leptons