Electrons in the Atom

by Cassidy Elizabeth Irvin

A bit about the atoms

The atom has many parts to it. the atom has the electron cloud where the energy levels have sub levels in which are orbitals and lastly the electrons.

There are three types of sub levels.(listed Below) and Each sub level can only contain a cretin amount of electron.


  • The S sub level can hold up to 2 electrons
  • The P sub level can hold up to 6 electrons
  • The D sub level can hold up to 10 electrons
  • The F sub level can hold up to 14 electrons

Steps to writting electron configurations

  1. First the element and its atomic number should be written.
  2. Then write the electron configuration according one of the methods shown below
  3. The exponents should add up to be equal to the atomic number.
  4. Once all of the above is finished you have successfully written an electron configuration.


AufBau method

AufBau was a scientist who stated that electrons that orbit one or more atoms fill the lower energy levels first so that the most stability is formed.

to use this method...

  1. Follow the arrows diagonally
  2. loop back up to the next diagonal row and continue the method

Periodic table method

In the periodic table method the sections of the periodic table(shown in picture) are divided into specific regions in where each sub level occurs.
  1. Use the number and level from each section
  2. The correct exponents for each number and sub level must be used
  3. Flow through the periodic table to complete the electron configuration

Orbital Notation

Friedrich Hund created the "School bus theory". In this theory he stated that Electrons will fill up the empty orbitals before pairing up with each other which produces more stability within the atom. However each sub level has a certain amount of orbitals.


  • The S sub level has
  • The P sub level has
  • The D sub level has
  • The F sub level has