Electron Configuration Worksheet (and Lots More!!)
Introduction:
An electron configuration is a method of indicating the arrangement of electrons surrounding a nucleus. A
typical electron configuration consists of numbers, letters, and superscripts with the following format:
1. The leading number indicates the energy level.
2. The next letter indicates the type of orbital: s, p, d, or f.
3. A superscript indicates the number of electrons in the orbital.
For example (1) —consider the electron configuration for helium: ls2
□ The 1 refers to the first energy level
□ The s refers to the s or spherical orbital
□ The 2 refers to the fact that there are two electrons present in that orbital
For example (2) —consider the electron configuration for oxygen: ls22s22p4
First orbital
□ The 1 refers to the first energy level
□ The s refers to the s or spherical orbital
□ The 2 refers to the fact that there are two electrons present in that orbital
Second orbital
□ The 2 refers to the second energy level
□ The s refers to the s or spherical orbital
□ The 2 refers to the fact that there are two electrons present in that orbital
Third orbital
□ The 2 refers to the second energy level
□ The p refers to the p or ‘dumbbell’ orbital
□ The 4 refers to the fact that there are four electrons present in that orbital
Steps for writing the short form: For example, the long form config for bromine is: 1s22s22p63s23p64s23d104p5
1. Find the noble gas of the atom immediately above the row of the atom in question. In this case argon:
2. Write the symbol for that noble gas in square brackets [Ar]
3. Write the remaining electron configuration for the remaining atoms [Ar] 4s23d104p5 YAYYYY!
IONS
Given the opportunity, an atom will gain or lose electrons in order to have eight electrons in its outer shell.
(The"Octet" Rule).
□ Do not assume an atom has done this unless there is evidence that it has (for example we refer to
it as an ‘ion’, the number of protons and electrons doesn’t balance, or there is a +/- charge on the
atomic symbol)
The outer shell is the highest numbered shell which has electrons in it (we call that the ‘outermost’ or ‘valence’
shell. Only s and p orbitals are part of the outer, valence shell.
An atom has the tendency to lose electrons (to another atom) or to gain electrons (from another atom) in order
to make the outer shell complete with eight electrons
□ Atoms with a complete outer shell (eight electrons) are considered stable.
□ Column 18 atoms naturally have eight electrons in their outer shell and are very stable which is why
they are often called “noble gases”. (Helium is the exception being stable with two electrons in its outer
shell.)
1
There is only 1 type of s orbital and it is a sphere: You should be able to sketch every occurrence of an s
orbital.
There are 3 types of p orbitals (often called sub-orbitals) Each sub-orbital can hold 2 electrons. You should be
able to sketch all of these as they occur together.
There are 5 types of d orbitals (often called sub-orbitals) Each d sub-orbital can hold 2 electrons. (You should
be able to recognize these as d orbitals—but not sketch them)
There are 7 types of f orbitals (often called sub-orbitals) Each f sub-orbital can hold 2 electrons. (You should
be able to recognize these as f orbitals—but not sketch them)
Electron Fill Map – Fill electrons from the 1s orbital using this path:
2
NAME: ______________________
PERIOD: ______
DATE: ___/___/___
Configuration Writing Practice
Write the electron configuration for each atom (note that there are no +/- signs so each atom is neutral).
1. Na
2. F
3. Zn
4. Br
5. Xe
6. Pick one of those atoms and clearly draw an electron orbital diagram for that atom in the space below:
Write the electron configuration for these ions. Remember that ions have a change in the total number of
electrons (positive ions have lost electrons and negative ions have gained electrons).
For Example: N3- is 1s2 2s2 2p6 has three extra electrons.
7.
O2-
8.
Mg2+
9.
B3+
10. K+
11. Pick one of those ions and draw an electron orbital diagram for that atom in the space below:
3
12. If each orbital shape (we often called these sub-orbitals) can hold a maximum of two electrons, how
many sub-orbitals are present in each of the following?
a. 2s
b. 5p
c. 4f
d. 3d
e. 4d
13. What is the shape of an s orbital?
14. How many s orbitals can there be in an energy level?
15. How many electrons can occupy an s orbital?
16. What is the shape of a p orbital?
17. How many p orbitals can there be in an energy level?
18. Which is the lowest energy level that can have an s orbital?
19. Which is the lowest energy level that can have a p orbital?
20. How many d sub-orbitals can there be in an energy level?
21. How many total d electrons can there be on an energy level?
22. Which is the lowest energy level having d orbitals?
23. How many f electrons can there be in an energy level?
24. Which is the lowest energy level having f orbitals?
25. How many f sub-orbitals can there be in an energy level?
4