17.
Explanation
Bonding and antibonding molecular orbitals are two types of molecular orbitals that result from the combination of atomic orbitals in a molecule. They have distinct characteristics that set them apart. Here are two key differences between bonding and antibonding molecular orbitals:
1. Energy Levels:
- Bonding Molecular Orbitals: Bonding molecular orbitals have lower energy levels compared to the atomic orbitals from which they are formed. This lower energy level indicates that electrons in bonding orbitals are more stable and contribute to the overall stability of the molecule.
- Antibonding Molecular Orbitals: Antibonding molecular orbitals have higher energy levels than the atomic orbitals. Electrons in antibonding orbitals are at higher energy states, which can make the molecule less stable. Antibonding orbitals weaken the bonding between atoms.
2. Electron Density Distribution:
- Bonding Molecular Orbitals: In bonding molecular orbitals, the electron density is concentrated between the nuclei of the bonded atoms. Electrons in these orbitals contribute to the attractive forces between the atoms, promoting bonding.
- Antibonding Molecular Orbitals: In antibonding molecular orbitals, the electron density is typically located away from the region between the nuclei. Electrons in antibonding orbitals contribute to repulsive forces between the atoms, counteracting the bonding forces.
These differences in energy levels and electron density distribution are crucial for understanding the overall stability and bonding characteristics of molecules. Bonding orbitals promote the formation of chemical bonds by lowering the energy of the system and concentrating electron density between
atoms, while antibonding orbitals, with their higher energy levels and electron density distributions, hinder bond formation and contribute to the weakening or breaking of existing bonds