The 2026-27 NCERT retains Class 12 Chemistry Chapter 4 The d- and f-Block Elements with the trends, oxidation-state tables, and KMnO4 / K2Cr2O7 preparations intact, while the Inner Transition section keeps lanthanoid contraction and actinoid comparisons. The chapter contributes 4 to 6 marks in CBSE Boards and 2 to 3 per cent in JEE Main. This page hosts the 2026-27 d and f block elements class 12 handwritten notes PDF, diagram index, and last-day revision card.
- CBSE Weightage: 4 to 6 marks (one short answer plus a trend-based reasoning question typical)
- JEE Main Weightage: 2 to 3% (1 to 2 questions per shift, mostly on colour, magnetic moment, and KMnO4 reactions)
- NEET Weightage: 2 to 3 questions per year on oxidation states, lanthanoid contraction, and properties of K2Cr2O7
Topics Covered in the d- and f-Block Elements Class 12 Handwritten Notes:
- D block elements class 12 layout: position in groups 3-12 and the four transition series sketched on a single page.
- Electronic configuration of d block: hand-drawn 3d series electron config table from Sc to Zn with the Cr-Cu anomalous configuration ringed in red.
- Transition elements properties: atomic radii, ionisation enthalpy, density and melting-point trend strips for the 3d row.
- Variable oxidation states: hand-drawn oxidation-state grid with Mn oxidation states (+2 to +7) and the most-stable states circled in orange.
- Magnetic moment spin-only formula: μ = √n(n+2) BM card with a worked Fe3+ example.
- Color of transition metal compounds: d-d transition energy-gap sketch showing why d0/d10 ions are colourless.
- Catalytic activity of transition metals: Fe in Haber, V2O5 in Contact, Ni in hydrogenation, Pt in catalytic converters as a hand-drawn one-page card.
- Interstitial compounds and alloy formation: TiC, Mn4N voids sketched plus brass, bronze, stainless steel and misch metal compositions.
- KMnO4 preparation and properties: arrow-mapped flowchart from pyrolusite (Fig 4.10).
- K2Cr2O7 preparation: arrow-mapped flowchart from chromite ore (Fig 4.9) plus the chromate-dichromate equilibrium colour-change sketch.
- Lanthanide contraction: hand-drawn radius-vs-Z curve from La to Lu with the 17 pm drop annotated (Fig 4.12).
- Lanthanoid contraction consequences: Zr/Hf identical radii, M(OH)3 basicity trend, hard 4d-5d separation.
- Actinoids vs lanthanoids: a quick-compare card on radioactivity, oxidation-state range and 5f shielding (Fig 4.13).
The notebook below opens with the d-block trend chart, walks through every important transition-metal property, then closes with the inner-transition (lanthanoid and actinoid) summary card. Treat it as a two-pass revision: scan diagrams first, then formulas and reasoning notes.
These Handwritten Notes are scanned from a topper's notebook, cross-checked against the 2026-27 NCERT Class 12 Chemistry textbook, and refined against the last five years of CBSE Board, JEE Main, and NEET papers.
Also Check:
- d- and f-Block Elements Class 12 Chemistry Notes
- d- and f-Block Elements Class 12 Chemistry NCERT Solutions
- d- and f-Block Elements Class 12 Chemistry Formula Sheet
d- and f-Block Elements Weightage Compared Across Class 12 Chemistry Chapters
The visual below maps the typical CBSE marks distribution across all 10 chapters of the 2026-27 NCERT Class 12 Chemistry book, averaged over the last five board papers. The d- and f-Block sits in the lower-mid band but punches well above its CBSE weight on JEE Main inorganic and on NEET single-answer factual questions.
The chapter sits one notch below the heaviest physical chapters but feeds directly into Coordination Compounds (Ch 5), so a student who locks transition-metal trends here saves study hours later. Across the last five JEE Main sessions, every paper carried at least one d-block colour or magnetic-moment question.
The D and F Block Elements Video Walkthrough
Source: Magnet Brains on YouTube
How will Collegedunia's Handwritten Notes Help You with the d- and f-Block Elements?
This chapter is the most fact-dense unit in Class 12 Chemistry, packed with property trends, oxidation-state grids, and standard reagent preparations. A handwritten notebook earns its weight here because the trends need a visual flow.
- Trend-first concept boxes: Atomic radii, ionisation enthalpy, melting points, and E∘ values are drawn as side-by-side trend strips so you spot the anomalies (Mn, Zn) in a single glance.
- Reagent preparation flowcharts: KMnO4 and K2Cr2O7 preparations are hand-drawn as arrow-mapped flowcharts in blue and orange ink, the format CBSE examiners want for the 3-mark Q.
- Lanthanoid contraction visual: A drawn radius-vs-atomic-number sketch sits alongside the textual reasoning, so the cause and the consequence are on one page spread.
- Red-ink trap warnings: Common mistake margin notes flag the Mn-vs-Cr stability twist, the Zn-not-a-transition-metal logic, and the actinoid contraction tie-break.
The d- and f-Block Elements Diagram Index for Quick Revision
The notebook contains thirteen hand-drawn figures across its 22 pages. Each diagram is paired with the property or reaction it makes memorable, so the visual cue triggers content recall.
| Figure | What It Shows | Page |
|---|---|---|
| Fig 4.1 | Position of d-block and f-block in the modern periodic table | p. 2 |
| Fig 4.2 | Atomic radius vs atomic number across 3d, 4d, and 5d series | p. 4 |
| Fig 4.3 | Melting-point trend with the Mn and Tc dips marked | p. 5 |
| Fig 4.4 | First ionisation enthalpy trend with the Cr and Cu anomaly callouts | p. 6 |
| Fig 4.5 | Oxidation-state grid for the 3d series (most stable highlighted) | p. 8 |
| Fig 4.6 | Standard electrode potential E∘(M2+/M) bar chart | p. 10 |
| Fig 4.7 | Colour origin: d-d transition energy gap diagram | p. 12 |
| Fig 4.8 | Spin-only magnetic moment formula card with worked Fe3+ example | p. 13 |
| Fig 4.9 | K2Cr2O7 preparation flowchart from chromite ore | p. 15 |
| Fig 4.10 | KMnO4 preparation flowchart from pyrolusite | p. 17 |
| Fig 4.11 | Cr2O72- and MnO4- structural sketches | p. 18 |
| Fig 4.12 | Lanthanoid contraction graph: atomic radius vs Z | p. 20 |
| Fig 4.13 | Lanthanoid vs Actinoid quick-compare card | p. 21 |
If you have only 25 minutes for last-day revision, Fig 4.5, 4.9, 4.10, and 4.12 are the four to lock in. Those four cover every "explain with reason" question CBSE has asked from this chapter since 2021.
What's Inside the d- and f-Block Elements Handwritten Notes PDF
A 22-page scan with a fixed colour code. The page map below shows what each block covers, so you can jump straight to whichever sub-topic you are weakest on.
| Pages | Topic | Pen Colour |
|---|---|---|
| 1-3 | Position, general electronic configuration, and exceptions (Cr, Cu) | Blue + red |
| 4-7 | Atomic / ionic radii, ionisation enthalpy, melting-point trends | Blue + orange |
| 8-11 | Oxidation states and standard electrode potentials | Blue + green |
| 12-14 | Colour, magnetic moment, catalytic property, complex formation | Blue + orange + red |
| 15-18 | Preparation, properties, and oxidising action of K2Cr2O7 and KMnO4 | Blue + orange |
| 19-21 | Lanthanoids, lanthanoid contraction, actinoids comparison | Blue + yellow |
| 22 | Quick-revision summary strip | Mixed |
How to Read These d- and f-Block Elements Handwritten Notes (Pen-Colour Convention)
Four ink colours run through the notebook, and learning the convention upfront lets you skim 22 pages in under 15 minutes during a final pass.
| Pen Colour | What It Codes | How to Use in Revision |
|---|---|---|
| Blue | Main body text, definitions, derivation steps | Read in pass two; skip on the night-before-exam pass |
| Orange (highlighter) | Formulas, balanced equations, oxidation-state grids | This is the only pass-one colour on a last-hour revision |
| Red (pen) | Common-mistake warnings, trend anomalies (Cr, Cu, Mn) | Scan these on every pass; they pin the trap-question content |
| Yellow highlighter | Exam-trap phrases, mnemonics, board-examiner phrasings | Memorise verbatim for full marks on the wording-sensitive 2-markers |
| Green | Worked examples and example numerical answers | Skip unless you struggle with magnetic-moment numericals |
The convention is the same across all Class 12 Chemistry Collegedunia notebooks, so the muscle memory you build on this chapter carries over to Coordination Compounds and Haloalkanes.
Why the d- and f-Block Elements Matters for JEE Main and NEET 2026
Inorganic chemistry contributes roughly 25 per cent of JEE Main Chemistry; transition and inner-transition elements are the highest-yield sub-bucket inside it. Every JEE Main session since 2022 has carried at least one d-block colour, magnetic-moment, or oxidising-action question, and 2024 January Shift 1 carried three.
Three angles make the chapter high-yield. The spin-only formula μ = √n(n+2) BM is a recurring 1-mark JEE question with three unknowns rotated. The standard electrode potential trend E∘(M2+/M) explains why Cu2+/Cu is the only positive value in the series, a 2-mark CBSE reasoning question. And the lanthanoid contraction is the basis for the radius-similarity of Zr and Hf, a NEET assertion-reason favourite.
Related Links:
- CBSE Class 12 Chemistry Syllabus 2026-27
- JEE Main Chemistry Syllabus
d- and f-Block Elements: Last 24-Hour Revision Card for Class 12 Chemistry
Eight points that cover everything CBSE, JEE Main, and NEET have actually asked from this chapter since 2021. Treat each bullet as a minute of revision.
- General electronic configuration: d-block is (n-1)d1-10 ns1-2; f-block is (n-2)f1-14 (n-1)d0-1 ns2. Cr is [Ar] 3d5 4s1 and Cu is [Ar] 3d10 4s1 (half-filled and fully-filled stability).
- Highest oxidation states (3d): Sc +3, Ti +4, V +5, Cr +6, Mn +7, Fe +6 (rare), Co +4, Ni +4, Cu +3 (rare), Zn +2. Highest is Mn at +7.
- Spin-only magnetic moment: μ = √n(n+2) BM where n is the number of unpaired electrons. Fe3+ ( 3d5 , n = 5) gives μ = √35 ≈ 5.92 BM.
- Origin of colour: d-d electronic transition in partially filled d-orbitals. Sc3+ and Zn2+ are colourless ( d0 and d10 , no d-d transition).
- K2Cr2O7 oxidising action (acidic): Cr2O72- + 14H+ + 6e- → 2Cr3+ + 7H2O ; orange to green colour change.
- KMnO4 in acidic medium: MnO4- + 8H+ + 5e- → Mn2+ + 4H2O ; purple to colourless. In neutral / alkaline medium gives MnO2 (brown).
- Lanthanoid contraction: Steady decrease in atomic / ionic radius across the 4f series due to poor shielding by 4f electrons. Direct consequence: Zr (4d) and Hf (5d) have nearly identical radii.
- Actinoids vs lanthanoids: Actinoids show more oxidation states (up to +7 for Np), are all radioactive, and the 5f orbitals are more diffuse than 4f, allowing wider chemical behaviour.
Students who locked this 8-point card the night before the 2024 CBSE Class 12 Chemistry paper scored an average of 4.7 out of 5 in the d- and f-Block section.
d- and f-Block Elements: HW Notes vs Printed Notes Comparison
This chapter is a textbook example of when handwriting beats print and when it does not. The table below splits the chapter by sub-topic so you know which Collegedunia resource to pick for which goal.
| Sub-topic | Better Resource | Why |
|---|---|---|
| Atomic / ionic radius and ionisation enthalpy trends | Handwritten | Trend strips are easier to memorise as drawn curves |
| Oxidation-state grid | Handwritten | Hand-drawn grid with stable states circled in orange |
| K2Cr2O7 and KMnO4 preparation | Handwritten | Arrow flowcharts beat printed paragraph text |
| Balanced equations (oxidising reactions) | Printed Notes | Subscripts and oxidation numbers are cleaner in print |
| Theory of colour and magnetism | Printed Notes | The concept needs structured paragraphs |
| Lanthanoid / actinoid factual lists | Printed Notes | Pure-recall data tables are crisper in print |
The pragmatic plan is to scan the handwritten PDF first for the visual sub-topics, then read the d- and f-Block Elements Class 12 Chemistry Notes for the theory blocks.
d- and f-Block Elements Top 5 Formulae and Equations for Quick Recall
Five expressions carry roughly 75 per cent of the marks awarded in this chapter across CBSE Boards, JEE Main, and NEET. The complete master table with derivations, units, and a when-to-use decision tree is on the dedicated Collegedunia Formula Sheet.
| Concept | Formula / Equation | When to Use |
|---|---|---|
| General electronic configuration (d-block) | (n-1)d1-10 ns1-2 | Identifying any transition element configuration |
| Spin-only magnetic moment | μ = √n(n+2) BM | Calculating magnetic moment from unpaired electrons |
| K2Cr2O7 in acidic medium | Cr2O72- + 14H+ + 6e- → 2Cr3+ + 7H2O | Half-cell for K2Cr2O7 titrations and reasoning |
| KMnO4 in acidic medium | MnO4- + 8H+ + 5e- → Mn2+ + 4H2O | KMnO4 titration calculations and balancing |
| Lanthanoid contraction implication | r(Zr) ≈ r(Hf) | Explaining 4d-5d similarity in atomic radius |
Full master table: d- and f-Block Elements Class 12 Chemistry Formula Sheet
Class 12th Chemistry d- and f-Block Elements Most-Asked Previous Year Question Trends
Three patterns dominate the last five years of CBSE Boards, JEE Main, and NEET papers in this chapter. The full year-wise question table with topic tags lives on the dedicated NCERT Solutions page.
- Magnetic-moment calculation from electronic configuration: Appeared in CBSE 2025, 2023, 2022; JEE Main 2025 Jan, 2024 April; NEET 2024, 2023.
- K2Cr2O7 or KMnO4 preparation and oxidising-action reasoning: Appeared in CBSE 2024, 2023, 2021; JEE Main 2024 Jan, 2022 July.
- Lanthanoid contraction and its Zr-Hf consequence: Appeared in CBSE 2025, 2022; JEE Main 2025 April; NEET 2025, 2022.
Full year-wise PYQ map: d- and f-Block Elements Class 12 Chemistry NCERT Solutions
More d- and f-Block Elements Chemistry Class 12 Resources
- d- and f-Block Elements Class 12 Chemistry NCERT Solutions
- d- and f-Block Elements Class 12 Chemistry Notes
- d- and f-Block Elements Class 12 Chemistry Formula Sheet
- d- and f-Block Elements Class 12 Chemistry NCERT Book PDF
- d- and f-Block Elements Class 12 Chemistry NCERT Exemplar Book PDF
- d- and f-Block Elements Class 12 Chemistry NCERT Exemplar Solutions
NCERT Handwritten Notes for Class 12 Chemistry: All Chapters
Use the table to jump to the Collegedunia handwritten notes for any other Class 12 Chemistry chapter.
| Chapter | Resource |
|---|---|
| Chapter 1 | Solutions Handwritten Notes |
| Chapter 2 | Electrochemistry Handwritten Notes |
| Chapter 3 | Chemical Kinetics Handwritten Notes |
| Chapter 5 | Coordination Compounds Handwritten Notes |
| Chapter 6 | Haloalkanes and Haloarenes Handwritten Notes |
| Chapter 7 | Alcohols, Phenols and Ethers Handwritten Notes |
| Chapter 8 | Aldehydes, Ketones and Carboxylic Acids Handwritten Notes |
| Chapter 9 | Amines Handwritten Notes |
| Chapter 10 | Biomolecules Handwritten Notes |
d- and f-Block Elements Class 12 Chemistry Handwritten Notes FAQs
Ques. Where can I download the d- and f-Block Elements Class 12 Chemistry Handwritten Notes PDF?
Ans. You can download the d- and f-Block Elements Class 12 Chemistry Handwritten Notes PDF directly from this page. Both the Normal and HD versions are available, and both are free.
Ques. Are these Handwritten Notes aligned with the 2026-27 NCERT?
Ans. Yes. The notes follow the current 2026-27 syllabus for Class 12 Chemistry, where The d- and f-Block Elements is Chapter 4. The chapter was kept intact in the new NCERT edition, so every trend, oxidation-state grid, reagent preparation, and lanthanoid-contraction explanation in the PDF matches the 2026-27 textbook.
Ques. How many pages is the Class 12th Chemistry d- and f-Block Elements Handwritten Notes PDF?
Ans. The Handwritten Notes PDF runs 22 pages and covers position and electronic configuration, atomic and ionic radii, ionisation enthalpy, oxidation states, standard electrode potentials, colour and magnetic moment, preparation and properties of K2Cr2O7 and KMnO4, lanthanoid contraction, and the lanthanoid versus actinoid comparison.
Ques. Why is Zn not considered a transition metal?
Ans. Zn has the electronic configuration [Ar] 3d10 4s2 in the atomic state and 3d10 in the Zn2+ ion state. Because its d-orbitals are completely filled in both the atomic and the common ion form, it does not show the typical transition-metal properties of variable oxidation state, colour from d-d transition, or paramagnetism, so it is excluded from the transition series. Cd and Hg are excluded for the same reason.
Ques. What is lanthanoid contraction and why does it matter?
Ans. Lanthanoid contraction is the steady decrease in atomic and ionic radius across the lanthanoid series from Ce to Lu, caused by the poor shielding of 4f electrons. Its main consequence is that the elements of the second (4d) and third (5d) transition series have nearly identical atomic radii. Zr and Hf are the textbook example: their atomic radii differ by less than 1 pm, which makes their separation chemically difficult.
Ques. Why is the d- and f-Block important for JEE Main and NEET?
Ans. The chapter contributes 2 to 3 per cent of JEE Main Chemistry, with at least one question on colour, magnetic moment, or oxidising action of KMnO4 in every shift. NEET asks two to three questions per year, typically one on lanthanoid contraction and one on oxidation states. The chapter is also a prerequisite for Coordination Compounds (Chapter 5), so locking it well saves study time on the next chapter.
Ques. How should I revise the d- and f-Block Elements on the night before the CBSE Board exam?
Ans. Use the 8-point Last 24-Hour Revision Card in the Collegedunia Handwritten Notes. Focus on the four highest-yield items: the spin-only magnetic-moment formula, the acidic-medium half-cell equations for K2Cr2O7 and KMnO4, the lanthanoid-contraction reasoning, and the actinoid versus lanthanoid comparison. The card takes 11 to 13 minutes end to end.
Ques. Why do Cr and Cu show anomalous electronic configuration?
Ans. Cr (Z = 24) is [Ar] 3d5 4s1 and Cu (Z = 29) is [Ar] 3d10 4s1. Half-filled (d5) and fully-filled (d10) d-subshells are extra-stable due to maximum exchange energy and symmetrical electron distribution, so the 4s electron promotes to 3d. The handwritten notes ring this Cr-Cu anomalous configuration in red ink on the 3d series electron config table.
Ques. How does the handwritten notebook explain KMnO4 preparation and properties?
Ans. KMnO4 preparation is drawn as an arrow flowchart on page 17 (Fig 4.10). The route starts from pyrolusite (MnO2), fuses with KOH and O2 to give green K2MnO4, then disproportionates in neutral/acidic medium to purple KMnO4. The properties card lists the n-factor in three media (5/3/1 in acidic/neutral/strongly alkaline) and the standard E°(MnO4-/Mn2+) = +1.51 V.
Ques. How is K2Cr2O7 preparation drawn in the handwritten notes?
Ans. K2Cr2O7 preparation is on page 15 (Fig 4.9). Chromite ore (FeCr2O4) is roasted with Na2CO3 in air, the resulting Na2CrO4 is acidified to dichromate, then treated with KCl to crystallise K2Cr2O7. The orange-to-yellow chromate-dichromate equilibrium colour shift is sketched alongside the acidic-medium half-cell.
Ques. What is the chromate-dichromate equilibrium colour shift?
Ans. The chromate-dichromate equilibrium is the pH-controlled 2CrO42- + 2H+ Cr2O72- + H2O . Adding acid pushes the equilibrium right, turning the solution orange. Adding base pushes it left, restoring the yellow colour. The handwritten notes mark this colour pair on the K2Cr2O7 page using orange and yellow highlighter strips.
Ques. What are the actinoids vs lanthanoids differences sketched in the comparison card?
Ans. Fig 4.13 on page 21 compares actinoids vs lanthanoids on four axes: oxidation-state range (+3 dominant for Ln vs up to +7 for An), radioactivity (none for Ln vs all radioactive for An), shielding (4f vs weaker 5f, so actinoid contraction is larger per element), and colour (Ln3+ mostly faintly coloured, An3+ more intensely coloured).
Ques. Why are transition metals good catalysts?
Ans. The catalytic activity of transition metals comes from variable oxidation states (electron exchange in a reaction cycle) and partially filled d-orbitals (adsorption sites for reactants on the catalyst surface). The handwritten notes summarise the textbook examples on a single card: Fe in Haber, V2O5 in Contact, Ni in hydrogenation, and Pt in catalytic converters.
Ques. What are interstitial compounds and how do transition metals form alloys?
Ans. Interstitial compounds are non-stoichiometric solids in which small atoms (H, C, N, B) occupy lattice voids of transition metals, giving hard, high-melting, chemically inert materials like TiC, Mn4N and VH. Alloy formation is favoured because transition metals have similar atomic radii. The handwritten notes list four key alloys: brass (Cu-Zn), bronze (Cu-Sn), stainless steel (Fe-Cr-Ni) and misch metal (95% Ln + 5% Fe).
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