Why is the third ionisation energy of manganese exceptionally high ?

Why is third ionisation enthalpy of manganese exceptionally high ?

Why is third ionisation enthalpy of manganese exceptionally high?

Why is the third ionisation energy of manganese (At No. 25) unexpectedly high?

Give reasons for the following observations : The third ionisation enthalpy of manganese (Z = 25) is exceptionally high

Why is the third ionization energy of manganese (at no 25) unexpectedly high?

How would you account for the following ? The third ionization enthalpy of manganese (Z = 25) is exceptionally high.

Why the third ionization energy of manganese (atomic number 25) unexpectedly high?