# Bond Orders of Isoelectronic Species

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1. Aug 7, 2015

How and why do isoelectronic species have the same bond order? My book cites an example that says that F2 and O2 -2 (oxygen molecule ion) has a bond order of 1. I understand how fluorine gas has a bond order of 1. But how does the oxygen molecule ion have a bond order of 1? Is it because they both have the same number of valence electrons?
Thanks!

2. Aug 7, 2015

### Titan97

You can calculate bond order using Molecular orbital theory.
Bond Order = [(number of electrons occupying bonding orbitals)-(number of electrons in anti-bonding orbitals)]/2
Try to find the bond order of $O_2$, ${O_2}^-$ and ${O_2}^{2-}$ yourself.

3. Aug 7, 2015