Answer
The Lewis structure `:O=O:` does not represent the ground state of the oxygen molecule, but rather an excited state configuration.
Work Step by Step
The given Lewis structure for O₂ (oxygen molecule) with the double bond, `:O=O:`, corresponds to an excited state of the oxygen molecule, not the ground state.
To explain this, we need to consider the molecular orbital energy-level diagram for the oxygen molecule.
In the ground state of the oxygen molecule, the molecular orbital energy-level diagram shows the following configuration:
```
σ*2p
π*2p
σ2p
π2p
σ2s
1s
```
In this ground state configuration, the oxygen molecule has two unpaired electrons in the π*2p orbitals, which is the most stable arrangement.
The Lewis structure you provided, `:O=O:`, corresponds to an excited state of the oxygen molecule, where the electrons are paired up in the σ*2p orbital instead of being in the π*2p orbitals.
This excited state configuration has a higher energy compared to the ground state configuration, as the electrons are occupying a higher-energy molecular orbital (σ*2p) instead of the lower-energy π*2p orbitals.
Therefore, the Lewis structure `:O=O:` does not represent the ground state of the oxygen molecule, but rather an excited state configuration.
