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Mo Theory

Posted: Sun Nov 22, 2015 9:31 pm
by zach devereux 1C
How do you know which orbitals to fill out in the diagram.?

Re: Mo Theory

Posted: Sun Nov 22, 2015 10:04 pm
by Joyce Xiong 4C
Hey there!

To fill out a molecular orbital diagram, first you need to find out how many valence electrons there are in the molecule you are drawing the diagram for. You count the electrons like how you would if you weren't doing a molecular orbital diagram, so for the molecule B2, there are 6 valence electrons total (3 from each boron atom). Then, knowing how many valence electrons you will need in your diagram, you fill them on the molecular orbitals from lowest to highest energy. Then, you fill out the orbitals (starting from orbitals of the lowest energy) based on Pauli Exclusion Principle and Hund's rule. Each orbital can not hold more than two electrons with opposite spin, and for orbitals with the same energy (the pi bonding and anti-bonding orbitals in the case), you fill each orbital with an electron first before adding a second electron in either orbital.