The melting point of Cu is higher than that of Zn because:A. The s, p as well as d-electrons of copper are involved in metallic bonding.B. The atomic volume of copper is higher.C. The d-electrons of copper are involved in metallic bonding.D. The s as well as d-electrons are involved in metallic bonding.

The correct answer is C. The d-electrons of copper are involved in metallic bonding.

The melting point of a metal is primarily determined by the strength of its metallic bonds. In metals, the outermost electrons of the atoms are delocalized and form a "sea" of electrons that are free to move throughout the structure. This delocalized electron cloud is responsible for the characteristic properties of metals, including their high electrical and thermal conductivity.

In the case of copper (Cu), its d-electrons play a significant role in metallic bonding. Copper is a transition metal, and transition metals have partially filled d-orbitals. These d-electrons contribute to the metallic bonding by overlapping with the delocalized electron cloud.

On the other hand, zinc (Zn) is not a transition metal. It does not have any partially filled d-orbitals. Instead, it has a completely filled d-orbital configuration. This full d-orbital configuration means that the d-electrons of zinc do not contribute significantly to metallic bonding.

Therefore, the involvement of d-electrons in metallic bonding is the primary reason why the melting point of copper is higher than that of zinc.