The electronic configuration $3d^{10}4s^0$ is exhibited by which of the following ions?

The correct order of the first ionization enthalpies is:

The electronic configuration of the last element of the volatile metal group is:

Define transition elements and inner transition elements.

The set having ions which are coloured and paramagnetic both is :

Four successive members of the first row transition elements are listed below with their atomic numbers. Which one of them is expected to have the highest $E^{o}_{M^{3+} / M^{2+}}$ value?