1. Bohr Model

2. Hydrogen Model  A hydrogen atom is a single electron and proton. One negative charge One positive charge  Assume that the discrete energies are associated with stable orbits. Coulomb potential

3. Circular Orbit  Electrons are in stable circular orbits. Coulomb force is centripetal forceCoulomb force is centripetal force Radius rRadius r Allow nucleus charge ZAllow nucleus charge Z

4. Quantized Angular Momentum  Bohr assumed that the angular momentum of the circular orbit was quantized. Circumference 2  rCircumference 2  r Quantum number n is an integerQuantum number n is an integer  This combined with the force equation to get quantized radii.

5. Discrete Jumps  Atomic transitions follow jumps between Bohr levels. Radius to potential

6. Hydrogen Energy Levels  Most common emission is from transitions between free electrons and bound states.  Emission series for hydrogen have defined names for inner energy number n. Lyman 1 Balmer 2 Paschen 3 Brackett 4 next