Introduction to d- and f-Block Elements for JEE Main

The d- and f-Block Elements chapter is a core topic of Class 12 Inorganic Chemistry and holds significant importance in JEE Main examinations. This chapter deals with the chemistry of transition metals (d-block elements) and inner transition metals (f-block elements), focusing on their electronic configuration, properties, oxidation states, compounds, and applications.

Although theory-oriented, this chapter can be highly scoring if students understand periodic trends and key concepts clearly.

Direct Links to Download JEE Main - Chapter Wise Previous Year Papers Chemistry (PDF)

► Click “Download Here” next to your subject to access the free PDF.

Position of d- and f-Block Elements in the Periodic Table

• d-Block elements are placed between s- and p-block elements and occupy Groups 3 to 12.

• f-Block elements are placed separately at the bottom of the periodic table and include:

  • Lanthanides

  • Actinides

Their unique position results in special electronic and chemical properties.

General Electronic Configuration of d-Block Elements

The general electronic configuration of d-block elements is:

(n−1)d¹⁻¹⁰ ns¹⁻²

This configuration explains:

• Variable oxidation states

• Formation of colored ions

• Complex formation

• Magnetic properties

JEE Main often tests understanding of electronic configuration-based trends.

Characteristics of Transition Elements

Transition elements show several unique properties:

• Variable oxidation states

• High melting and boiling points

• Good conductivity

• Formation of alloys

• Catalytic behavior

These properties arise due to the presence of partially filled d-orbitals.

Oxidation States of Transition Elements

Transition elements show multiple oxidation states due to the small energy difference between ns and (n−1)d orbitals.

Examples:

• Iron shows +2 and +3

• Manganese shows +2 to +7

JEE Main frequently includes trend-based and comparison questions from this topic.

Trends in Transition Elements

Important trends include:

• Atomic and ionic radii

• Ionization enthalpy

• Enthalpy of atomization

• Electronegativity

Understanding these trends helps in solving assertion-reason questions.

Magnetic Properties of d-Block Elements

Magnetic behavior depends on the number of unpaired electrons.

Types:

• Paramagnetic

• Diamagnetic

Questions based on magnetic moment calculation are common in JEE Main.

Colored Ions of Transition Elements

Transition metal ions are colored due to:

• d-d transitions

• Charge transfer transitions

This concept is important for conceptual MCQs.

Catalytic Properties of Transition Metals

Transition metals and their compounds act as catalysts due to:

• Variable oxidation states

• Ability to form intermediate complexes

Examples:

• Iron in Haber process

• Vanadium oxide in Contact process

JEE Main may ask application-based questions.

Important Compounds of Transition Elements

Key compounds include:

• Potassium permanganate (KMnO₄)

• Potassium dichromate (K₂Cr₂O₇)

Important topics:

• Preparation

• Properties

• Oxidizing nature

These compounds are frequently asked in JEE Main exams.

Introduction to f-Block Elements

f-Block elements are also known as inner transition elements and include:

• Lanthanides (4f series)

• Actinides (5f series)

They show unique properties due to the gradual filling of f-orbitals.

Lanthanides – Properties and Trends

Lanthanides show:

• +3 oxidation state

• High magnetic properties

• Similar chemical behavior

Lanthanide Contraction

Lanthanide contraction refers to the gradual decrease in atomic and ionic radii across the lanthanide series.

Effects include:

• Similar size of elements

• Difficulty in separation

• Influence on d-block elements

This is a very important concept for JEE Main.

Actinides – General Properties

Actinides include elements from thorium to lawrencium.

Key features:

• Radioactive nature

• Variable oxidation states

• Formation of complex compounds

Conceptual questions may appear from this topic.

Comparison Between Lanthanides and Actinides

Key differences include:

• Oxidation states

• Radioactivity

• Bonding nature

Comparison-based MCQs are common in JEE Main.

Applications of d- and f-Block Elements

These elements are widely used in:

• Alloy formation

• Nuclear reactors

• Catalysts

• Magnets

• Glass and ceramics

Application-based questions may be asked.

Important JEE Main Preparation Tips for d- and f-Block Elements

• Focus on periodic trends

• Memorize important compounds and oxidation states

• Practice assertion-reason questions

• Revise electronic configurations regularly

• Solve previous year JEE Main questions

Why Study d- and f-Block Elements from Studentbro.in?

Studentbro.in offers:

• Simplified theory notes

• Trend-based explanations

• Exam-oriented content

• MCQs and PYQs

• Quick revision material

All content is aligned with the JEE Main syllabus.

Conclusion

The d- and f-Block Elements chapter is a conceptual yet scoring topic in Class 12 Chemistry for JEE Main. A strong understanding of trends, properties, and key compounds can help students score confidently.

With structured explanations and exam-focused material, Studentbro.in makes learning d- and f-Block Elements easier and more effective.