In the series Sc(Z = 21) to Zn (Z = 30), the enthalpy of atomisation of zinc is the lowest, i.e., `126 kJ mol^(-1)`, why ?

Explanation

In zinc `(3d^(10)4s^(1))` d-orbital is complete so the electrons of d-orbital are not involved in , bonding. So, metallic bond is weaker than the other elements of the series, where the electrons ' of d-orbitals are involved in metallic bonds. So, enthalpy of atomisation of zinc is lowest in its transition series.