Which is the incorrect statement regarding ionization energy of d series elements 

Outer electronic configuration of Cr is $3{\mathrm{d}}^{5}4{\mathrm{s}}^1$ and after losing one electron, it achieves a stable half-filled configuration. Therefore, the first ionization of Cr is lower than Mn.

The outer configuration of Pd is $4{\mathrm{d}}^{10}$ and that of Rh is $4{\mathrm{d}}^{8}5{\mathrm{s}}^1.$Because of having filled outermost shell, the ionization energy of Pd is more than Rh. 

The first ionization energies of 5d series is more than 4d series and 3d series because 5s have 4f orbitals that have the weak shielding, hence electrons of 5d are strongly attracted towards the nucleus.

Tungsten (W) has more ionization energy than molybdenum (Mo) because of the poor shielding of the inner orbitals.