Question

O_2 molecule has:

• A. 10 bonding electrons, 6 antibonding electrons and is diamagnetic.
• B. 8 bonding electrons, 4 antibonding electrons and is paramagnetic.
• C. 10 bonding electrons, 6 antibonding electrons and is paramagnetic.
• D. 8 bonding electrons, 4 antibonding electrons and is diamagnetic.

Hint:

For paramagnetic molecules, there must be unpaired electrons in the molecular orbitals. In contrast, diamagnetic molecules have all electrons paired.

Answer 1

The Correct Option is C

For the \( \text{O}_2 \) molecule, we follow the molecular orbital theory. The electron configuration for \( \text{O}_2 \) is as follows: \[ \text{Molecular Orbitals of O}_2: \sigma_{1s}^2, \sigma_{1s}^*2, \sigma_{2s}^2, \sigma_{2s}^*2, \sigma_{2p_z}^2, \pi_{2p_x}^2, \pi_{2p_y}^2, \pi_{2p_x}^*1, \pi_{2p_y}^*1 \] From this configuration, there are 10 bonding electrons and 6 antibonding electrons. The presence of two unpaired electrons in the antibonding orbitals (\( \pi^* \)) indicates that the molecule is paramagnetic.