Chemistry · Chemical Bonding

The correct answer is CFT (Crystal Field Theory) because it focuses on the interaction of transition metal ions with surrounding ligands and does not provide a mechanism for the formation of sigma and pi bonds. In contrast, both MOT (Molecular Orbital Theory) and VBT (Valence Bond Theory) are applicable theories that explain how these types of bonds are formed through orbital interactions. VSEPR (Valence Shell Electron Pair Repulsion) theory, while useful for predicting molecular shape, does not deal with the bonding mechanisms directly. Therefore, CFT is the only theory listed that does not explain sigma and pi bond formation.

Although Both Option C and Option D is correct according to our textbook, but in Ofiicial UHS MDCAT 2025 key, this question has Option D as correct answer, so we will follow the official to ensure the key alingment and authenticity

Molecular Orbital Theory (MOT) describes the formation of bonds through the combination of atomic orbitals to form molecular orbitals, which can be either bonding or antibonding. It accounts for both sigma and pi bonds.

Valence Bond Theory (VBT) explains bond formation through the overlap of atomic orbitals, resulting in the formation of sigma and pi bonds. It is a key theory used to understand chemical bonding.

The Valence Shell Electron Pair Repulsion (VSEPR) theory is used to predict the geometry of molecules based on electron-pair interactions. It does not directly explain the formation of sigma and pi bonds.

Crystal Field Theory (CFT) primarily explains the electronic structure of transition metal complexes and does not address the formation of sigma and pi bonds in the context of covalent bonding. Thus, it is the correct choice for this question.

Although Both Option C and Option D is correct according to our textbook, but in Ofiicial UHS MDCAT 2025 key, this question has Option D as correct answer, so we will follow the official to ensure the key alingment and authenticity