3.3 Review & Practice
Name________________________________
Electron Configuration & Orbital Box Diagrams
Period_______Date_____________________
Part I: True and False - If the statement is true write “true.” If it is false, change the underline word or
words to make it correct.
_______________ 1. The Pauli Exclusion Principle states that an orbital can hold a maximum of two
electrons.
_______________ 2. The sum of the superscripts in an electron configuration represents the total number
of neutrons in the atom or ion.
_______________ 3. The Aufbau Principle states that electrons are added one at a time to the highest
energy orbitals available until all the electrons of the atom have been accounted for.
_______________ 4. An orbital box diagram uses arrows to represent the spin of the electrons
_______________ 5. The ground state is the least stable energy state of an atom.
_______________ 6. According to Hund’s Rule, electrons occupy equal energy orbitals so that a
maximum number of unpaired electrons result.
Part II: Completion – Identify the elements (atoms) that have the following electron configurations.
Write the chemical symbol for each element in the space provided.
_________ 7. 1s22s22p3
________ 12. 1s22s22p63s23p64s23d104p5
_________ 8. 1s22s22p63s23p2
________ 13. 1s22s22p6
_________ 9. 1s22s22p63s23p64s23d10
________ 14. 1s22s22p63s23p64s23d4
_________ 10. 1s22s22p63s23p64s2
________ 15. 1s22s22p63s23p64s23d104p65s24d10
_________ 11. 1s22s22p63s23p64s23d104p65s24d105p66s24f145d6
Part III: Short Answer
16. Explain the Aufbau Principle, Pauli Exclusion Principle and Hund’s Rule when predicting an electron
configuration.
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Part IV: Write the Electron Configuration on the first line and Orbital Box Diagram on the second line.
x
2
17.magnesium
2
6
2
1s 2s 2p 3s
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y
z
     
1s
2s
2p
3s
18. oxygen
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19. aluminum
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20. argon
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21. scandium
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22. phosphorus
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23. potassium
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Part V: Write the electron configuration for each of the following elements and then write the number of
unpaired electrons each atom has. Write the electron-dot diagram around each element’s symbol.
24.
Na
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25.
As
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26.
Ir
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27.
Se
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28.
Bi
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29.
Hg
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