1. As we move from left to right along the transition metal series, melting point first increases as the number of unpaired d electrons available for metallic bonding increases, reach a maximum value and then decreases, as the d electron pairs up and become less available for bonding.
2. For example, in the first series the melting point increases from Scandium to a maximum of 2183 K for Vanadium, which is close to 2180K for chromium.
3. Manganese in 3d series and has low melting point. The maximum melting point at about the middle of transition metal series indicates that d5 configuration is favorable for strong interatomic attraction.
