d- and f-Block Elements

About this unit

The d-block (groups 3–12) contains the transition metals, and the f-block contains the lanthanoids and actinoids. These elements include structural metals like iron, coinage metals, and many industrial catalysts. The unit explains their electronic configurations and the trends in size, ionisation enthalpy and oxidation states, along with their characteristic properties: colour, magnetism, complex formation and catalytic activity. It also covers two important compounds, potassium dichromate and potassium permanganate.

Key ideas

• General configuration (n−1)d¹⁻¹⁰ns¹⁻²; exceptions such as Cr and Cu.
• Variable oxidation states and trends in E° values.
• Coloured ions, paramagnetism and spin-only magnetic moment μ = √[n(n+2)] BM.
• Catalytic properties, interstitial compounds and alloys.
• Preparation, properties and oxidising reactions of K₂Cr₂O₇ and KMnO₄.
• Lanthanoid contraction and its consequences; comparison of lanthanoids and actinoids.

How to prepare

Learn the 3d series configurations, the common oxidation states and colours of key ions. Practise spin-only magnetic moment calculations. Write balanced ionic equations for dichromate and permanganate as oxidising agents in acid. Be ready for reasoning questions such as why Zn is not a typical transition element or why Zr and Hf are so similar.