Final answer:
The indicated bond is formed by overlapping two ns atomic orbitals, two np atomic orbitals, and an ns and an np orbital. This forms a sigma bond (s bond) with concentrated electron density along the internuclear axis.
Step-by-step explanation:
The indicated bond formed by overlap of two ns atomic orbitals, two np atomic orbitals, and an ns and an np orbital, where n = 2. Maximum overlap occurs between orbitals with the same spatial orientation and similar energies. The overlap of an s orbital and a p orbital forms a sigma bond (s bond), as illustrated in Figure 8.4. A sigma bond is a covalent bond in which the electron density is concentrated in the region along the internuclear axis.