Question

Write four characteristics of transition elements.

Hint:

The unique properties of transition metals are due to the presence of partially filled d-orbitals.

Answer 1

Step 1: Definition.
Transition elements are d-block elements that have partially filled d-orbitals in their ground state or in one of their oxidation states.
Step 2: Characteristics.
Some important characteristics of transition elements are: \begin{enumerate} \item
Variable oxidation states: Transition metals commonly exhibit more than one oxidation state (e.g., Fe$^{2+}$ and Fe$^{3+}$). \item
Formation of coloured compounds: Due to d–d electronic transitions, many transition metal salts and complexes are coloured. \item
Catalytic properties: They act as good catalysts because of variable oxidation states and ability to provide active sites (e.g., V$_2$O$_5$ in contact process). \item
Formation of complex compounds: Transition metals form coordination complexes with ligands due to availability of vacant d-orbitals (e.g., [Fe(CN)$_6$]$^{3-}$). \end{enumerate} Conclusion:
Thus, transition elements show variable oxidation states, coloured ions, catalytic activity, and complex formation as their main characteristics.