Question

What are the transition elements and why are they called so?

Answer 1

1. Transition elements are those elements belonging to the d-block of the periodic table where electrons enter the (n − 1)d subshell.
2. They are called transition elements because they lie between highly electropositive s-block elements and highly electronegative p-block elements, showing a transition in properties.
3. These elements typically have partly filled d-orbitals in their atoms or common ions in chemically significant oxidation states.
4. Examples include scandium to zinc in the 3d series, yttrium to cadmium in the 4d series, etc.
5. Zinc, cadmium, and mercury are not considered transition elements as they lack partly filled d-orbitals in common oxidation states.
6. Thus, their position and electronic configuration define them as transition elements, reflecting transitional chemical behavior between s and p-block elements.