Final answer:
The central carbon atom in the structure O=C=O, or CO₂, exhibits sp hybridization. This is because it has two regions of high electron density from the two double bonds with oxygen and no lone pairs, resulting in a linear molecular geometry and a bond angle of 180°.
Step-by-step explanation:
The hybridization around the central carbon atom in the molecule represented by the structure O=C=O (carbon dioxide, CO₂) can be determined by examining the regions of high electron density around the central atom. In this case, the central carbon atom forms two double bonds with the oxygen atoms, each counting as a single region of electron density, and there are no lone pairs on the carbon atom. Based on the Valence Shell Electron Pair Repulsion (VSEPR) theory, two regions of electron density will arrange themselves as far apart as possible, leading to a bond angle of 180° and a linear shape for the molecule.
Therefore, the hybridization of the central carbon atom in CO₂ is sp hybridization, as any central atom surrounded by just two regions of valence electron density exhibits this type of hybridization. This is consistent with other linear molecules such as HgCl₂ and HCCH.