AIIMS 2018 Chemistry Molecular Orbital Theory MCQ Question

O₂ is paramagnetic because it has two unpaired electrons in its π*2p antibonding molecular orbitals, which allows it to be attracted to a magnetic field. In contrast, O₂ is not diamagnetic (B) since diamagnetic substances have all electrons paired. The bond order of O₂ is calculated as (number of bonding electrons - number of antibonding electrons) / 2, resulting in a bond order of 2, making options C and D incorrect, as bond orders of 3 and 1 do not accurately reflect the molecular structure of O₂.