Steps to write the electron configuration of a neutral atom 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.
1. Locate the atomic number
1. Locate the atomic number
1. Locate the atomic number
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.
Using the following electron configuration chart we are going to build the configuration for potassium, K , 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
Now we just have to follow the arrows until we sum 19 electrons:
Now we just have to follow the arrows until we sum 19 electrons: 1s 2 1s 2
Now we just have to follow the arrows until we sum 19 electrons: 1s 2 2s 2 2 s 2
Now we just have to follow the arrows until we sum 19 electrons: 1s 2 2s 2 2p 6 2p 6
Now we just have to follow the arrows until we sum 19 electrons: 1s 2 2s 2 2p 6 3s 2 3 s 2
Now we just have to follow the arrows until we sum 19 electrons: 1s 2 2s 2 2p 6 3s 2 3p 6 3 p 6
Now we just have to follow the arrows until we sum 19 electrons: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 4 s 1
Now we just have to follow the arrows until we sum 19 electrons: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 The sum of the superscripts must be 19! 4 s 1
Practice writing the electron configuration of any other atom from th e periodic table! For more resources on chemistry visit: Periodic table with names http://periodictablewithnames.net