Name: ________________________
Per: _____ Date: _______________
Bohr Models, Aufbau Diagrams, and Electron Configurations
Use a periodic table and the information below to complete the following activity. For each element
given, draw a Bohr Model and an aufbau diagram.
Bohr Model – Include the number of protons and neutrons (round the atomic mass to the nearest
whole number) in the nucleus, and the correct number of electrons in each energy level.
Aufbau Diagram – Create an aufbau diagram following the three rules:
This is information that you will need to know. If you will not look at this assignment when you are
studying, I would suggest copying down these rules in your notes! 
1. Aufbau Principle – _____________ occupy the orbitals of ____________ energy first.
2. Pauli Exclusion Principle – each orbital can only hold _________ _________________ at a time
and they must have a ______________ ______________.
3. Hund’s Rule – electrons occupy orbitals of the ____________ _____________ in a way that
makes the number of electrons with the same __________ _____________ as _____________ as
possible.
Example:
Nitrogen
Bohr Model
Aufbau Diagram
2p __ __ __
p+ = 7
0
n =7
2s __
2 e- 5 e1s __
Electron Configuration
Complete: 1s2 2s2 2p3
Nobel Gas: [He] 2s2 2p3
Valence Electron: 2s2 2p3
Bohr Model
Aufbau Diagram
Fluorine
Electron
Configuration
Complete:
5p __ __ __
4d __ __ __ __ __
5s __
4p __ __ __
3d __ __ __ __ __
4s __
Nobel Gas:
3p __ __ __
3s __
2p __ __ __
2s __
1s __
Valence Electron:
Bohr Model
Aufbau Diagram
Tin
Electron
Configuration
Complete:
5p __ __ __
4d __ __ __ __ __
5s __
4p __ __ __
3d __ __ __ __ __
4s __
Nobel Gas:
3p __ __ __
3s __
2p __ __ __
Valence Electron:
5p __ __ __
Complete:
2s __
1s __
Oxygen
4d __ __ __ __ __
5s __
4p __ __ __
3d __ __ __ __ __
4s __
Nobel Gas:
3p __ __ __
3s __
2p __ __ __
Valence Electron:
5p __ __ __
Complete:
2s __
1s __
Sodium
4d __ __ __ __ __
5s __
4p __ __ __
3d __ __ __ __ __
Nobel Gas:
4s __
3p __ __ __
3s __
2p __ __ __
Valence Electron:
5p __ __ __
Complete:
2s __
1s __
Aluminum
4d __ __ __ __ __
5s __
4p __ __ __
3d __ __ __ __ __
Nobel Gas:
4s __
3p __ __ __
3s __
2p __ __ __
2s __
1s __
Valence Electron:
Bohr Model
Boron
Aufbau Diagram
Electron
Configuration
Complete:
Nobel Gas:
Valence Electron:
Argon
Complete:
Nobel Gas:
Valence Electron:
Iron
Complete:
Nobel Gas:
Valence Electron:
Calcium
Complete:
Nobel Gas:
Valence Electron:
Iodine
Complete:
Nobel Gas:
Valence Electron: