In a molecule of carbon dioxide CO2 , the central atom is carbon. Carbon has four valence electrons, and in CO2, it forms two double bonds with the two oxygen atoms. To form these double bonds, carbon undergoes sp hybridization. In sp hybridization, one s orbital and one p orbital from the central atom mix to form two new sp hybrid orbitals. These two sp hybrid orbitals form linear bonds with the oxygen atoms, resulting in a linear molecular geometry with a bond angle of 180 degrees.