The valence bond theory only explains covalent bonds.It doesn't explain ionic or metallic bonding. Use VBT to describe the bonding in butane(C4H8).
In butane (C4H8), the bonding between carbon and hydrogen atoms can be explained using the valence bond theory. The carbon atoms in butane each have four valence electrons and are able to form four covalent bonds.
Each carbon atom forms sigma bonds with three hydrogen atoms and one other carbon atom. These sigma bonds are formed by the overlap of the carbon's sp3 hybrid orbitals with the 1s orbitals of the hydrogen atoms.
In addition, there are also pi bonds present in the molecule. The pi bonds are formed by the overlapping of unhybridized p orbitals on the carbon atoms. In butane, there are two pi bonds present, one between each pair of carbon atoms.
Overall, the bonding in butane is described as a combination of sigma and pi bonds formed through the overlap of hybridized and unhybridized orbitals, respectively, on the carbon and hydrogen atoms.