Transition metals are not characterized by

The atomic number of $Pd$ is $46$. The atomic numbers of the elements lying immediately above and below it in the same group are,respectively,.....................

The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?

The elements with the highest and the lowest enthalpy of atomisation respectively, for first row transition elements are:

Which property is exhibited only by transition elements?

The number of $4f$ electrons in the ground state electronic configuration of $Gd^{2+}$ is ........ .
[Atomic number of $Gd=64$]