Describe the rules needed when determining the electron configuration.

Answer 1

1. Find the number of electrons the element has by looking on the periodic table-if the substance is neutral/not charged it will be equal to the number of protons (atomic number)
2. Know the order in which electrons fill orbitals-look up order electrons fill to find the diagram you can draw
3. I use a "game-board method" with the periodic table that I find easier and would be happy to explain to you
4. know how many electrons fill each type of orbital
5. s-2
6. p-6
7. d-10
8. f-14
9. From there, keep filling the orbitals in order until you have used the total amount of electrons you found in step one
10. To write this configuration, specify the energy level and orbital listed in the filling diagram, using a superscript above the energy level/orbital combination to demonstrate how many electrons it has
11. Example- Mg
12. From the periodic table, we see the atomic number is 12-so it has 12 protons and is uncharged so therefore has 12 electrons
13. From the order filling diagram you can easily find online- we see that these electrons will fill in the following order:
14. 1s, 2s, 2p,3s, 3p....
15. Therefore the electron configuration is:
16. 1s²2s²2p⁶3s²
17. if we add up the superscripts we can see that this used all 12 electrons

** there are some exceptions to these rules as orbitals are most stable empty, full, or half-filled and certain elements will fill differently to find this stability