The document summarizes the development of modern atomic models from Rutherford's model to the current quantum mechanical model. It describes Bohr's planetary model which explained emission spectra by quantizing electron energy levels. Later, quantum mechanics with Schrodinger and Heisenberg refined Bohr's model using wave and cloud descriptions of electrons in distinct orbitals. The rules of quantum mechanics such as Aufbau principle and Hund's rule are explained. Finally, it shows how the location of s, p, d and f orbitals relate to the periodic table and electron configurations.

1. Modern Model of The Atom
• Rutherford’s Model: Pro’s and
Con’s
• Improved on (Thomson’s)
Plum Pudding Model
• Protons inside, Electrons
outside
• Couldn’t explain how
electrons stayed outside

2. Niels Bohr and The Planetary Model of
The Atom
• Inspired by Niels
Bohr
the work of
Bunsen and
Kirchoff
• Emission
spectra of
Spectrometer
elements Bunsen and Kirchoff

3. Bohr: Electrons are ‘quantized’
• Emission spectra
Emission Spectra
• Electrons in of a Few
Elements
Energy Levels
• Electrons
• Ground State Ground State
vs. Excited and Excited State
State

4. Bohr Model=Planetary Model
• Bohr’s Model Pro’s and
Con’s
• Explained small atoms
well
• Failed to explain where
electrons were in larger
atoms Nitrogen Atom

5. Quantum Mechanic Model of The Atom
• Erwin Schrodinger and
Werner Heisenberg Schrodinger
• 1925-30
• Refined Bohr’s Model
• Wave or Cloud Model of
Electrons
• Electrons in orbitals of
Heisenberg
differing energy

6. Quantum Mechanic Rules
• Energy level (n=energy level)
• Type of orbital (s,p,d,f) s-orbital
• Shape of orbital p-orbital
• sphere, dumbbell, rosette, d-orbital
complex
f-orbital
• Number of Electrons in orbital
Shapes
• s=2; p=6; d=10; f=14 of Orbitals

7. Quantum Mechanic Rules Continued...
• Aufbau Principle
• electrons occupy orbitals of lower energy first
• (s<p<d<f)
• Hund’s Rule
• electrons occupy adjacent orbitals before pairing
• Pauli Exclusion Principle
• electrons occupying the same orbital must have
opposite spin

8. The Periodic Table:
Where Are The S, P, D, and F Orbitals?
s-orbitals d-orbitals p-orbitals
f-orbitals

9. Orbital Diagrams and
Electron Configurations
• orbital diagrams
show us where
bonding occurs
• We’ll do elements
1-10
• You will do
elements 11-18,
tonight
Aufbau Diagram