Name: _________________________________
Period: _______
Date: _____________
Introduction to Electron Configuration
Where are electrons REALLY?
Real World Analogies
Electron
Student in a College
Dorm
Stadium
You in School
Number per Energy
Level
Number of Electrons
That Can Fit in Each
Energy Level’s Orbital
Diagram
Energy Levels
Orbitals
Orbitals
Orbital Name
Three Rules of Electron Configuration
Aufbau
Principle
Pauli
Exclusion
Principle
Hund’s
Rule
STEPS OF ELECTRON CONFIGURATION
Element
Maximum
Number of
Electrons
Helium
Boron
Oxygen
Total # of
electrons
# of
Energy
Levels
1s
2s
2p
3s
3p
4s
3d
4p
32
4
2
2
6
2
6
2
10
6
2
5
1
2
2
2
2
1
Fluorine
Magnesium
Phosphorus
Argon
For the elements above, write out the electron configuration in the proper notation.
1. Helium: 1s2
2. Boron: 1s22s22p1
3. Oxygen: _______________________________________________
4. Fluorine: _______________________________________________
5. Magnesium: _______________________________________________
6. Phosphorus: _______________________________________________
7. Argon: _______________________________________________
Reminder:
Element
Total # of
electrons
# of
Energy
Levels
1s
2s
2p
3s
3p
4s
3d
4p
32
4
2
2
6
2
6
2
10
6
Maximum
Number of
Electrons
Write the electron configurations for the following elements using the steps listed on the previous page.
1. Lithium: _______________________________________________
2. Nitrogen: _______________________________________________
3. Sodium: _______________________________________________
4. Silicon: _______________________________________________
5. Potassium: _______________________________________________
6. Carbon: _______________________________________________
SWITCH IT UP! Identify the following elements based on their electron configurations.
1. 1s22s2
____________________
2. 1s22s22p63s23p4
____________________
3. 1s1
____________________
4. 1s22s22p63s23p1
____________________
5. 1s22s22p63s23p64s2
____________________
6. 1s22s22p6
____________________
7. 1s22s22p63s23p5
____________________
Practice (this time with d and f!)
Element
Total # of
electrons
1s
2s
2p
2
5
2
2
2
1
Helium
Boron
Silicon
Calcium
Iron
Zinc
Bromine
Krypton
3s
3p
Write out the following configurations without the table.
1. Titanium: ____________________________________________
2. Selenium: ____________________________________________
3. Silver: ____________________________________________
4. Iodine: ____________________________________________
Keep it going!!!
Write the electron configuration for the following elements.
Element
Ag
Br
Ba
Fr
U
Mo
Hf
Am
Cf
Es
Au
Rn
# e-
Electron Configuration (EC)
4s
3d
4p
CHALLENGE ROUND: Electron Configuration with Ions!
An atom’s electron configuration changes depending on whether the atom is neutral, positive, or negative.
 Negatively charged atoms have more electrons
 Positively charged atoms have fewer electrons
Fill in this table for the following IONS.
Total # of
Element
1s
electrons
Li1+
2s
2p
3s
3p
4s
O2N3Mg2+
Be2+
S2Cl-
In the space below, write the unabbreviated electron configurations of the following elements:
1. Sodium
________________________________________________
2. Iron
________________________________________________
3. Bromine
________________________________________________
4. Barium
________________________________________________
5. Neptunium
________________________________________________
In the space below, write the abbreviated electron configurations of the following elements:
6. Cobalt
________________________________________________
7. Silver
________________________________________________
8. Tellurium
________________________________________________
9. Radium
________________________________________________
10. Lawrencium
________________________________________________
3d
4p