Question

All transition metals are d-block elements but all d-block elements are not transition elements. explain.

Answer 1

All transition metals are d-block elements but all d-block elements are not transition elements because all d- block elements which don't have completely filled d- orbitals are not counted as transition, So such elements are exceptional. Eg, Zn, CD and Hg.

Answer 2

Explanation:

Transition elements are the elements which have incompletely filled d-orbital.

For example, Scandium has electronic configuration $[Ar]4s^{2}3d^{1}$ is a transition element but Zinc has electronic configuration $[Ar]4s^{2}3d^{10}$.

As zinc has completely filled d-orbital so it is not considered as a transition element.

Similarly, cadmium and mercury have completely filled d-orbital. So, they are not considered as transition elements.

Therefore, it is true that all transition metals are d-block elements but all d-block elements are not transition elements.