Final answer:
Bonding orbitals are lower in energy, more stable, and node-free, leading to bond formation between atoms; antibonding orbitals are higher in energy, less stable, and contain nodes, which can destabilize bonds. These interactions in solids form valence and conduction bands, important in conductivity.
Step-by-step explanation:
The character of bonding and antibonding orbitals differs significantly in terms of energy levels, presence of nodes, and effects on atomic interactions. Bonding molecular orbitals are lower in energy than the atomic orbitals from which they form because they result from in-phase combinations of atomic orbitals. This decreased energy level indicates a more stable state, contributing to the bond formation between atoms. In contrast, antibonding molecular orbitals are higher in energy and less stable, formed from out-of-phase combinations of atomic orbitals, which can destabilize bonds. Bonding orbitals have no nodes perpendicular to the internuclear axis, while antibonding orbitals feature at least one such node, reflecting the regions of zero electron probability. In solids, these interactions lead to the formation of valence and conduction bands with numerous bonding and antibonding orbitals, affecting the material's properties such as conductivity.