Hybridization and Molecular Orbital Energy Level Diagram Cheat Sheet/ Study Guide Let's do some practice with Molecular Orbital Diagrams. O₂ Molecular Orbital Diagram Calculate the number of valence electrons. The number of valence electrons is equal to the group number the element is in. Oxygen is in group 6 and has 6 valence electrons. There are two oxygens, making the total number of valence electrons 12, Choose the correct molecular orbital diagram based on the element. A