# What are electron configurations?

May 28, 2014

Electron Configurations are an organized means of documenting the placement of electrons based upon the energy levels and orbitals groupings of the periodic table.

The electron configuration for the first 10 elements

H $1 {s}^{1}$
He $1 {s}^{2}$
Li $1 {s}^{2} 2 {s}^{1}$
Be $1 {s}^{2} 2 {s}^{2}$
B $1 {s}^{2} 2 {s}^{2} 2 {p}^{1}$
C $1 {s}^{2} 2 {s}^{2} 2 {p}^{2}$
N $1 {s}^{2} 2 {s}^{2} 2 {p}^{3}$
O $1 {s}^{2} 2 {s}^{2} 2 {p}^{4}$
F $1 {s}^{2} 2 {s}^{2} 2 {p}^{5}$
Ne $1 {s}^{2} 2 {s}^{2} 2 {p}^{6}$

The Coefficient tells us the Energy Level (Row) of the periodic table
The s or p tell us the orbital block.
The superscript tells us the number of electrons in the orbital.

The s orbitals Groups 1 & 2 (columns) can hold 2 electrons
The p orbitals Groups 13 - 18 (columns) can hold 6 electrons
The d orbitals Groups 3-12 (columns) can hold 10 electrons.
The f orbitals can hold 14 electrons.

Each energy level must be filled before moving up an energy level.
Each orbital group must fill before moving to the next orbital group.

1s
2s 2p
3s 3p
4s 3d 4p
5s 4d 5p
6s 4f 5d 6p
7s 5f 6d 7p

Germanium

#1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^2.
Germainum is in the 4th row Energy Level of the periodic table. The element is in the 2nd column of the p block, Group IVA (Column 13).