Configurations of Electrons
and Quantum #s KEY
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A typical electron configuration consists of numbers, letters, and superscripts (example-1s22s22p5), and describes
how electrons are arranged in an atom.
The coefficient number (in front) indicates the (energy level, sub-energy level, number of electrons). (circle one)
A letter indicates the (energy level, sub-energy level, number of electrons). (circle one)
A superscript indicates the number of electrons in the orbital.
For the element represented by the electron configuration: 1s22s22p5, identify the following:
(a.)
# Energy Levels where electrons can be found two
(b.)
# Electrons in 2p
5
(c.)
Total Electrons
9
(d.)
Element
Fluorine
Identifying Elements from Electron Configuration
Identify the element described by each electron configuration.
1.
1s22s22p63s1
2.
1s22s22p63s23p64s23d104p65s24d6
3.
1s22s22p63s23p64s23d8
4.
[Xe] 6s2
5.
[Ar]4s23d104p3
Sodium (Na)
Ruthenium (Ru)
Nickel (Ni)
Barium
Arsenic (As)
Electron Configuration Errors
Determine if the following electron configurations are correct (Y/N). If NO, explain what is wrong.
6.
1s22s22p63s23p64s24d104p65s1
N
should be 3
7.
1s22s22p63s3
N
3s can only hold 2e-, not 3e-
8.
[Rn] 7s25f96d2
N
6d1 comes before 5f which should also hold 10e-
9.
[Ar] 5s24d105p5
N
Krypton is the noble gas to use
20.
[Xe] 6s24f10
N
5d1 comes before 4f which should also hold 9e-
Electron Configurations for Neutral Atoms
Write the entire, full electron configuration (do not use the Noble Gas shortcut) for each neutral atom given. Neutral
atoms have the same number of protons and electrons.
21.
22.
23.
24.
25.
Na
Sr
Cl
Ti
Pd
1s22s22p63s1
1s22s22p63s23p64s23d104p65s2
1s22s22p63s23p5
1s22s22p63s23p64s23d2
1s22s22p63s23p64s23d104p65s24d8
Electron Configurations for Neutral Atoms
Use the Noble Gas shortcut to write the electron configuration for each neutral atom given.
26.
27.
28.
29.
30.
Na
Sr
Cl
Ti
Pd
[Ne]3s1
[Kr]5s2
[Ne]3s23p5
[Kr]4s23d2
[Kr]5s24d8
More Quantum Practice
 Quantum #s predict the location of a specific electrons by identifying where we can find the electron 90_ % of
the time.
 The electrons with the highest amount of energy are the electrons most likely to react in chemistry.
 These electron is called the valence electrons, and are the electrons that fill last in Aufbau diagrams and
electron configurations.
31.
Which electron is highest in energy? (circle one)
1s1 2s1 2p1 3p1 2d1 3d1
32.
Arrange the following in order of lowest energy to highest energy.
3s1 3p1 4s1 3d1 4p1 4d1
33.
34.
35.
35.
36.
For this element, 1s22s22p63s23p64s23d8 , the electrons that have the highest energy are located in which energy
level ? third (write number)
For this element, 1s22s22p63s23p64s23d8 , the electrons that fill last are located in which type of sub-energy
level? d (write letter)
For this element, 1s22s22p63s23p64s23d8 , how many valence electrons are there? 10
For this element, 1s22s22p63s23p64s23d8 , determine Principle (n) and Angular Quantum (l) #s of the electron
with the highest amount of energy.
n = _3__
l = ___2__
Complete the table for each element
Element
# valence e-
Sodium
1
3
s
Strontium
2
5
s
Chlorine
7
3
p
Titanium
4
3
d
Palladium
10
4
d
Principle Quantum # Angular Quantum #
for the electron with for the electron with
the highest energy
the highest energy