The correct order of configuration of O2 molecule according to MOT is

CONCEPT:

Molecular Orbital Theory (MOT) for O₂ Molecule

• Molecular Orbital Theory (MOT) explains the bonding in molecules by combining atomic orbitals to form molecular orbitals, which are spread over the entire molecule.
• In O₂, the molecular orbitals are formed by the combination of atomic orbitals from two oxygen atoms.
• The molecular orbitals are filled according to the Aufbau principle, Pauli exclusion principle, and Hund's rule.

EXPLANATION:

• The correct order of filling molecular orbitals for O₂ molecule is as follows:
  • σ 1s²: The bonding molecular orbital formed by the combination of 1s orbitals from both oxygen atoms.
  • σ* 1s²: The antibonding molecular orbital formed by the combination of 1s orbitals from both oxygen atoms.
  • σ 2s²: The bonding molecular orbital formed by the combination of 2s orbitals from both oxygen atoms.
  • σ* 2s²: The antibonding molecular orbital formed by the combination of 2s orbitals from both oxygen atoms.
  • σ 2p_z²: The bonding molecular orbital formed by the combination of 2p_z orbitals from both oxygen atoms.
  • π 2p_x² = π 2p_y²: The degenerate bonding molecular orbitals formed by the combination of 2p_x and 2p_y orbitals from both oxygen atoms.
  • π* 2p_x¹ = π* 2p_y¹: The degenerate antibonding molecular orbitals formed by the combination of 2p_x and 2p_y orbitals from both oxygen atoms.
• Based on this order, the correct configuration of the O₂ molecule is:

  σ 1s² < σ* 1s² < σ 2s² < σ* 2s² < σ 2p_z² < (π 2p_x² = π 2p_y²) < (π* 2p_x¹ = π* 2p_y¹)

Therefore, the correct order of configuration of O₂ molecule according to MOT is Option 2.