All Transition Elements are d-block elements but d-block elements are not transition

All transition elements are d-block elements, but all d-block elements do not transition elements.

D block elements are chemical elements having electrons filling to their d orbitals. 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. Transition elements are chemical elements that have incompletely filled d orbitals at least in one stable cation they form. Example: Zn, Cd, and Hg. The elements, whose who have incomplete d-orbital (d¹ to d⁹) at the time of formation of their stable ion, are called transition elements.

From the stimulus, Zn, Fe, Cu and Sc all are d-block elements because they have an electronic configuration of (n- l) d^1-10 ns^1-2 but, transition elements have an electronic configuration of d¹ – d⁹ at the time of formation of stable ion.

Zn(30) → 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s²

Zn²⁺ (30) → … …. … … … … … 3d¹⁰

Ni (28) → … … … … … … … … 4s²

Ni²⁺ (28) → … … … … … … … … 3d⁸

Fe (26) → 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²

Fe²⁺ (26) → … … … … … … … 3d⁶

Fc³⁺ (26) → … … … … … … … 3d⁵

Sc (21) → … … … … … … … 3d¹ 2s²

Sc³⁺ (21) → … … … … … … 3d⁹ 2s³

It is observed from the above electronic confirmation Se³⁺ and Zn²⁺ have electronic configuration of d⁶ and d¹⁰ which is not satisfied with the condition of becoming transition the elements. All transition elements are either paramagnetic or ferromagnetic.

Transition elements are the elements that have incompletely filled d-orbital. On the basis of this definition, scandium and zinc do not count as transition metals – even though they are members of the d block. For example, Scandium has electronic configuration [Ar] 4s²3d¹ is a transition element but Zinc has electronic configuration [Ar] 4s²3d¹⁰.

As zinc has totally filled d-orbital so it is not measured as a transition element. Similarly, cadmium and mercury have totally filled d-orbital. So, they are not measured as transition elements.

By contrast, copper, [Ar] 3d¹⁰4s¹, forms two ions. In the Cu⁺ ion the electronic structure is [Ar] 3d¹⁰. However, the more common Cu²⁺ ion has the structure [Ar] 3d⁹. Copper is definitely a transition metal because the Cu²⁺ ion has an incomplete d level. So, Sc and Zn are not transitioning elements.

D block elements may or may not form colorful complexes. Transition elements always form colorful complexes. Hence, they don’t show the variable oxidation states and can’t form a colored compound. So, all transition elements are d-block elements but all b-block elements are not transition elements.