The d- and f-Block Elements – Class 12 Chemistry Notes | Transition & Inner Transition Elements

 🧪 Chapter 8: The d- and f-Block Elements

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🔹 Introduction

d-block → Groups 3–12

f-block → Lanthanides and actinides

Known as transition and inner transition elements

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🔹 Electronic Configuration

General:

d-block: (n-1)d¹–¹⁰ ns¹–²

f-block: (n-2)f¹–¹⁴ (n-1)d⁰–¹ ns²

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🔹 Properties of d-block Elements

Variable oxidation states

Formation of colored compounds

Catalytic properties

Paramagnetic behavior

Complex formation

📌 Diagram: Table of transition elements and their oxidation states

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🔹 Important Series

First transition series: Sc to Zn

Second series: Y to Cd

Third series: La to Hg (excluding lanthanides)

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🔹 Lanthanides (4f series)

Elements: Ce (58) to Lu (71)

Properties:

+3 oxidation state common

Lanthanide contraction

Poor shielding by 4f electrons

📌 Diagram: Lanthanide contraction chart

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🔹 Actinides (5f series)

Elements: Th (90) to Lr (103)

Properties:

Radioactive

+3 to +6 oxidation states

Poor shielding, large atomic size

📌 Diagram: f-block placement in periodic table

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🔹 Comparison of d- and f-Block

Property d-Block f-Block

Oxidation States Variable Highly variable

Magnetic Nature Paramagnetic Strongly paramagnetic

Complex Formation Common Less common

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🔹 Applications

Catalysts (Fe in Haber process)

Pigments and dyes

Superalloys (Cr, V, Mo)

Nuclear fuels (U, Pu)

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🖼️ Important Diagrams to Include:

1. Periodic table highlighting d- and f-block

2. Oxidation states table of d-block elements

3. Lanthanide contraction graph

4. Comparison chart: d-Block vs f-Block

5. f-block layout in period

ic table

6. Color of transition metal compounds

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✍️ Written by: Shahid – Study with Shahid

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