According to the molecular orbital theory, the bond order of a molecule can be calculated using the formula:Bond order = Number of electrons in bonding orbitals - Number of electrons in antibonding orbitals / 2For the O2 molecule, there are 12 valence electrons 6 from each oxygen atom . The molecular orbital configuration for O2 is:1, 1*, 2, 2*, 1, 1Here, the bonding orbitals are 1, 2, 1, and 1, which contain a total of 8 electrons. The antibonding orbitals are 1* and 2*, which contain a total of 4 electrons.Using the bond order formula:Bond order = 8 - 4 / 2 = 2So, the bond order of the O2 molecule is 2.Regarding its paramagnetic or diamagnetic properties, a molecule is considered paramagnetic if it has unpaired electrons and diamagnetic if all electrons are paired.In the O2 molecular orbital configuration, there are two unpaired electrons in the 1 orbitals. Therefore, the O2 molecule is paramagnetic.