Analía Bellizzi – Chemistry Classes

Ronald Reagan Senior High School

Orbital Diagram Lab

IGCSE – Orbital Diagram Lab

IGCSE Lab – Electron_Configuration_Pogil 

The electrons in an atom occupy distinct principal energy levels. To be located in any each of these principal energy levels, electrons must have the required energy for the level. The principal energy levels are numbered 1, 2, 3, 4, 5, 6, and 7 for the atoms of the known elements.

Each principal energy level is subdivided into sublevels.  Each sublevel has its own energy requirement for electrons. The sublevels are labeled s, p, d, and f.

Within each sublevel there is a specific number of orbitals. The orbitals within a given sublevel have the same energy requirements for electrons. Each orbital can “hold” a maximum of two (2) electrons.

Rules for “filling” energy levels:

  1. Electrons enter the lowest principal energy level available.
  2. Within a principal energy level: electrons enter the lowest energy sublevel
  3. Within a sublevel: electrons enter each orbital one electron at a time until all orbitals have one electron. Then additional electrons enter each orbital until 2 electrons are in each orbital. Once all orbitals in a sublevel are filled (each with 2 electrons), the next electron enters the next higher energy sublevel.

The Aufbau diagram below illustrates the order of filling orbitals and sublevels.
Start at the 1s sublevel and follow the arrows. For example: 1s, 2s, 2p, 3s, 3p, 4s,
3d, 4p, 5s, etc.

aufbau diagram


To write the electron configurations for many elements.
To relate the electron configurations of the elements to their chemical behavior (whether the atom tends to lose or gain electrons).


  • Per student: electron configuration patterns
  • copy of the periodic table of elements
  • list of ions (atoms that have lost or gained electrons and have become charged particles; atoms that lose electrons become positively charged; atoms that gain electrons become negatively charged)


  • For each of the elements you are assigned, you must complete one electron
    configuration pattern.
    With the other members of your group, arrange the electron configuration grids according to increasing atomic number.