Transition metals generally have high melting points due to strong metallic bonding. However, zinc (Zn) has a relatively low melting point compared to other transition metals. This is because zinc has a full d-shell configuration, which results in weaker metallic bonding compared to metals that have partially filled d-orbitals.
- Vanadium (V) and Manganese (Mn), being earlier in the transition series, have higher melting points due to stronger metallic bonding.
- Copper (Cu) also has a relatively high melting point due to the strong bonding in its atomic structure.
Thus, the correct answer is Zinc (Zn), which has the least melting point in the 3d-transition series.