Electron Configuration with Examples

Electron Configuration with Examples

Electrons are not placed at fixed positions in atoms, but we can predict approximate positions of them. These positions are called energy levels or shells of atoms.

  • Lowest energy level is 1 and it is denoted with integer n=1, 2, 3, 4, 5, 6... or letters starting from K, L, N to Q.  An atom can have maximum 7 energy levels and electrons can change their levels according to their energies.
  • Each energy level has different number of electrons. For example, we can find number of electrons in four energy level with following formula; 2n2.

1st energy level has;

2n2=2.12=2 electrons

2nd energy level has;

2n2=2.22=8 electrons

3rd energy level has;

2n2=2.32=18 electrons

  • Electrons are located energy levels starting from the first energy levels. If one of the energy level is full, then electrons are placed following energy level.

Following pictures show location of electrons of atoms O and Mg.


electron configuration of atoms











Number of electrons at the outer shell of atom gives us following classification.


classification of atoms









Electron configuration of atom shows, shells, sub shells and number of electrons in sub shells. We examine electron configuration with following examples.

Example: Helium 2



1 is the principal quantum number or energy level (shell)

s is the sub-level or sub shell (Capacity of s sub shell is 2 electron)

2 shows the number of electrons in the s sub shell

Example: Chlorine 17


Coefficients 1, 2, 2, 3, and 3 are energy levels of Cl. As you can see "p" sub shell can have maximum 6 electrons.

Superscripts 2, 2, 6, 2 and 5 are electrons in the sub shells "s" and "p".

Example: Bromine 35


As you can see "d" sub shell can have maximum 10 electrons.

Example: Tantalum 73


As you can see "f" sub shell can have maximum 14 electrons.


Atomic Structure Exams and  Problem Solutions


examples of electron configuration diagram
electron shell levels
Helium atom showing the location of each particle
electron orbitals of MG
electron orbital diagram atoms
shell configuration for helium
atom 3rd shell
electron arrangement in atoms
2n2 energy shell
Mg Electron configuration
electron levels 2n2
electronic configuration of elements by 2n2
picture of atom with electron orbitals
2n2 chemistry
orbitals 2n2
sub-shell picture in atom
atom and 2n2
electron configuration diagram examples
chemistry electronic structure shell diagrams atoms
example of electron configuration using orbital and atomic diagram
pictures of atoms
show the electron configuration of helium
electron location
2n2 "energy shell"
electrons in atoms
electrons arrangement in atoms
mg electronic configurations
energy level diagram for atoms
picture of electron configuration for Mg
mg electronic structure diagram
electron location in atom
diagram to show the arrangement of electrons in the outermost energy level
mg atom
chemistry mg electron configuration
2n2 electronic configuration of all elements
electron orbitals and shells
atoms energy
electrons location in atom
electron configuration for Mg
electronic structure of helium
electron configuration mg
atom electron orbitals
electron configuration energy level diagram
location of electrons in an atom
atoms and their energy levels magnesium
shells orbitals 2n2
orbital arrangement number of electron in each
Mg electronic configuration