Sigma Bonding Electron density lies between the nuclei. A bond may be formed by s-s,p-p,s-p, or hybridized orbital overlaps. The bonding MO is lower in energy than the original atomic orbitals. The antibonding MO is higher in energy than the atomic orbitals. => Chapter 2 4 Chapter 2 4 Sigma Bonding • Electron density lies between the nuclei. • A bond may be formed by s-s, p-p, s-p, or hybridized orbital overlaps. • The bonding MO is lower in energy than the original atomic orbitals. • The antibonding MO is higher in energy than the atomic orbitals. =>