A complete guide on how to write the electron configuration of any atom. Find more resources on chemistry at http://periodictablewithnames.net

1. How to write the electron
configuration of an atom
By José @
Periodic table with names
http://periodictablewithnames.net

2. Steps to write the electron
configuration of a neutral atom
1. Find the atomic number of the atom, this
number must be equal to the number of
electrons on the atom.
The atomic number of an atom is located in the
upper left corner on the box for any of the
elements in the periodic table.

3. 1. Locate the atomic number

4. 1. Locate the atomic number

5. 1. Locate the atomic number

6. 2. Having the atomic number of the atom, follow
the Aufbau principle to assign the
corresponding number of electrons to each
orbital of the atom.

7. Using the following electron configuration chart
we are going to build the configuration for
potassium, K0, atomic number: 19.
Remember that the maximum number of
electrons for each orbital are:
2 for s
6 for p
10 for d
14 for f

8. Now we just have to
follow the arrows
until we sum 19
electrons:

9. Now we just have to
follow the arrows
until we sum 19
electrons:
1s2
1s2

10. Now we just have to
follow the arrows
until we sum 19
electrons:
1s2 2s2
2s2

11. Now we just have to
follow the arrows
until we sum 19
electrons:
1s2 2s2 2p6
2p6

12. Now we just have to
follow the arrows
until we sum 19
electrons:
1s2 2s2 2p6 3s2
3s2

13. Now we just have to
follow the arrows
until we sum 19
electrons:
1s2 2s2 2p6 3s2 3p6
3p6

14. Now we just have to
follow the arrows
until we sum 19
electrons:
1s2 2s2 2p6 3s2 3p6 4s1
4s1

15. Now we just have to
follow the arrows
until we sum 19
electrons:
1s2 2s2 2p6 3s2 3p6 4s1
The sum of the
superscripts must be
19!
4s1

16. Practice writing the electron configuration of
any other atom from the periodic table!
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