Final answer:
Chromium has a higher melting point among 4th period transition metals due to its electronic configuration that results in strong metallic bonds and a stable half-filled d-shell. Low oxidation state compounds of Cr have ionic characteristics contributing to their strength and high melting points.
Step-by-step explanation:
The reason why chromium (Cr) has a higher melting point among the transition metals in the 4th period can be related to its electronic structure and bond nature. Chromium has an electron configuration of [Ar] 4s¹3d⁵, where the half-filled d-shell imparts additional stability and a strong metallic bonding due to the symmetrical distribution of unpaired electrons.
These unpaired electrons increase the strength of the metallic bonds within the crystal lattice resulting in a high melting point. Additionally, the concept that transition metal halides with low oxidation numbers form more ionic bonds, which are stronger, suggests that chromium's common +3 oxidation state would contribute to the stability and high melting point of its compounds, such as Cr²S₃ containing Cr³+ ions. However, higher oxidation states tend to be less stable in lighter transition metals of the first series.