* Structure: CO2 has a linear structure with the carbon atom in the center and two oxygen atoms bonded to it at 180-degree angles.

* Hybridization: To accommodate this linear geometry and the two double bonds with oxygen, the carbon atom needs to have two hybrid orbitals that point in opposite directions. This is achieved through sp hybridization, where one s orbital and one p orbital from the carbon atom combine to form two sp hybrid orbitals.

* Bonding: The two sp hybrid orbitals on the carbon atom form sigma bonds with the oxygen atoms. The remaining two p orbitals on the carbon atom form pi bonds with the oxygen atoms, resulting in the double bonds.

So, the carbon atom in CO2 uses two sp hybrid orbitals to form the sigma bonds with the oxygen atoms, resulting in a linear structure.