Final answer:
The molecular geometry of CO₂ is linear, as determined by the VSEPR theory, because it has a central carbon atom with two bonding pairs of electrons and no lone pairs, causing the oxygen atoms to be 180° apart.
Step-by-step explanation:
Predicting the molecular geometry of carbon dioxide (CO₂) involves applying the Valence Shell Electron Pair Repulsion (VSEPR) theory. The carbon atom in the center forms two double bonds, one with each oxygen atom. According to VSEPR theory, the electron pairs in the double bonds repel each other and want to be as far apart as possible.
Considering that there are no lone pairs of electrons on the central carbon atom, and that both electron groups around it are double bonds, CO₂ is designated as AX2. This means there are two bonding pairs on the central atom. The molecular geometry that minimizes repulsions in this scenario is a linear shape, with the oxygen atoms positioned 180° apart from each other.
The molecular structure of CO₂ can thus be predicted to be linear due to these considerations. By understanding such factors, one can deduce molecular shapes using the VSEPR model, explaining physical and chemical behaviors of molecules.