The order of filling of molecular orbitals $\ce{O2}$ by MOT is this :
But from it, how can I deduce that there is one sigma and one pi bond in an oxygen molecule ?
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Sign up to join this communityThe order of filling of molecular orbitals $\ce{O2}$ by MOT is this :
But from it, how can I deduce that there is one sigma and one pi bond in an oxygen molecule ?
Overall bond order equals number of electrons that occupy bonding orbitals minus numer of electrons that occupy antibonding orbitals divided by two.
Now you can apply the same concept indivudually:
For s molecular orbitals, both electron pairs "cancel out".
For p molecular orbitals, you have 2 electrons in sigma bonding orbitals and none in sigma antibinding orbitals, which means (2-0)/2 = 1 sigma bond. Also, you have 4 electrons within pi bonding orbitals and only 2 electrons within pi antibonding orbitals, which means (4-2)/2 = 1 pi bond. This yields the result that you expected.