D-Block and F-Block Elements – NEET Chemistry Class 12

D-block and F-block elements are transition and inner-transition elements, respectively. These elements are crucial in NEET because they appear frequently in questions related to oxidation states, complex formation, electronic configuration, and chemical reactivity.

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Introduction to D-Block Elements

• Definition: Elements with partially filled d-orbitals.

• General Properties:

  • Variable oxidation states

  • Formation of colored ions and complexes

  • Catalytic activity

  • Metallic nature and high melting points

• Examples: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn

Electronic Configuration of D-Block Elements

• General configuration: (n–1)d¹⁻¹⁰ ns⁰⁻²

• Transition elements show incomplete d-orbitals in ground or common oxidation states.

• Explains variable oxidation states and formation of colored compounds.

Chemical Properties of D-Block Elements

1. Oxidation States:

   • Increases across the period

   • Maximum oxidation state = group number

2. Complex Formation:

   • Form coordination compounds with ligands (e.g., [Fe(CN)₆]³⁻)

3. Catalytic Activity:

   • Many act as catalysts in industry (Fe in Haber process, V₂O₅ in Contact process)

4. Magnetic Properties:

   • Unpaired electrons cause paramagnetism

Introduction to F-Block Elements

• Definition: Elements with partially filled f-orbitals.

• Subdivisions:

  • Lanthanides (4f series): Ce to Lu

  • Actinides (5f series): Th to Lr

• General Properties:

  • Similar chemical behavior within the series

  • +3 oxidation state predominant in lanthanides

  • Actinides show multiple oxidation states

Electronic Configuration of F-Block Elements

• Lanthanides: [Xe] 4f¹⁻¹⁴ 5d⁰⁻¹ 6s²

• Actinides: [Rn] 5f¹⁻¹⁴ 6d⁰⁻¹ 7s²

• F-orbital filling explains similar chemical properties and lanthanide contraction

Trends in D-Block and F-Block Elements

1. Atomic and Ionic Size:

   • D-block: Decrease across period, slight increase down group

   • F-block: Lanthanide contraction affects size and properties

2. Oxidation States:

   • D-block: Multiple, variable

   • F-block: Lanthanides mostly +3, actinides vary

3. Magnetic Properties:

   • Number of unpaired electrons determines paramagnetism

4. Complex Formation:

   • D-block: Strong tendency to form coordination compounds

   • F-block: Rarely form stable complexes

Importance for NEET Preparation

• Questions often include oxidation states, electronic configuration, color, and catalytic activity.

• F-block elements are frequently tested in trends, lanthanide contraction, and separation techniques.

• D-block and F-block concepts form the basis for transition metal chemistry in Class 12.

Previous Year NEET Questions – Insights

• Determining oxidation states and electronic configuration

• Predicting magnetic properties and color of complexes

• Explaining trends in melting points, density, and reactivity

• Applications of transition metals and lanthanides in industry and medicine

Study Tips for Students

1. Memorize General Trends – Oxidation states, atomic size, magnetic properties

2. Understand Electronic Configurations – Helps predict chemical behavior

3. Practice Previous Year NEET Questions – Focus on application-based problems

4. Learn Industrial Applications – Catalysts, alloys, and medical uses

5. Focus on Lanthanide Contraction and Actinide Series – Frequently asked in NEET

Conclusion

Mastering D-Block and F-Block Elements is essential for NEET success. These elements are highly scoring in NEET because they combine conceptual clarity, numerical problems, and real-life applications. A strong understanding ensures confidence in transition metal and inner transition chemistry.