D and F Block Elements for NEET: Unit 11 Trends and Traps
D and f block elements are the transition elements (the d block, groups 3 to 12) and the inner transition elements (the lanthanoids and actinoids, the f block), and together they are Unit 11 of NEET Chemistry. They are not removed from the syllabus. Unlike most inorganic units, this one names two compounds you must know in detail: KMnO4 and K2Cr2O7. This guide shows what Unit 11 covers, with real data to learn the trends from.
Are d and f block elements in the NEET 2027 syllabus?
Yes. The d and f block elements are Unit 11 of the Chemistry section in the NMC syllabus for NEET (UG) 2026, dated 22 December 2025. No 2027 syllabus exists yet, so this is the current text. It sits between Unit 10 (p block elements) and Unit 12 (coordination compounds) in the inorganic block.
The NEET (UG) 2026 Information Bulletin answers the obvious next question in its FAQ: there was no change in the syllabus of NEET (UG) 2026 with respect to the previous year. As of 29 October 2026, the NEET (UG) public notices still list nothing about the 2027 cycle. Some websites already quote 2027 registration dates, but none of them is NTA. Study the current wording, and re-check it the day NTA publishes the 2027 bulletin.
Why do students ask whether this unit was cut? Because textbooks and syllabus files changed in recent years, and many "deleted topics" lists mix the two. Only the exam syllabus decides what NEET can ask. Our NEET 2027 deleted syllabus guide goes through that list line by line.
What exactly does Unit 11 ask you to know?
Unit 11 is short for the d and f block elements, but it is not vague. It names every property it wants, and it splits cleanly into two halves. Here is the official wording, unpacked.
| Syllabus phrase (Unit 11) | What it means in practice | What to be able to do |
|---|---|---|
| Transition Elements: general introduction, electronic configuration, occurrence and characteristics | Groups 3 to 12, with the first row (scandium to zinc) as the focus | Write the configuration of any element from Sc to Zn, including the two exceptions |
| General trends in properties of the first-row transition elements | Physical properties, ionization enthalpy, oxidation states, atomic radii | Explain why a property rises, falls or stays flat across Sc to Zn |
| Colour, catalytic behaviour, magnetic properties | Behaviour that comes from partly filled d orbitals | Predict whether an ion is coloured or paramagnetic from its d electron count |
| Complex formation, interstitial compounds, alloy formation | Why these metals bind ligands, trap small atoms and mix with each other | Give one reason and one example for each |
| Preparation, properties, and uses of K2Cr2O7 and KMnO4 | The only two compounds the unit names | Know each preparation route, colour, oxidation state of the metal and main uses |
| Inner Transition Elements: Lanthanoids | Electronic configuration, oxidation states, lanthanoid contraction | State the common +3 state, the exceptions, and what the contraction does |
| Actinoids | Electronic configuration and oxidation states | Say why actinoids show more oxidation states than lanthanoids |
Compare that with Unit 10 on p block elements, which names no compound at all. For the d and f block elements, the two named compounds are where the syllabus is most specific, so give them proper time.
Two other units lean on this one. Unit 9 places s, p, d and f block elements in the present form of the periodic table and builds the idea of ionization enthalpy. Unit 20, on practical chemistry, includes the titrations "oxalic acid vs KMnO4" and "Mohr's salt vs KMnO4", the preparation of Mohr's salt, and the cations Cu2+, Fe3+, Zn2+ and Ni2+ in salt analysis. Revise those three units together and the d and f block elements stop feeling like an isolated chapter.
Which elements count as d and f block elements?
The d block elements are those whose last electron enters a d orbital, in groups 3 to 12. The f block elements are the two rows printed below the main table: the lanthanoids, which follow lanthanum, and the actinoids, which follow actinium. All data below is from the PubChem periodic table, run by the US National Institutes of Health.
| Series | Elements | Outer configuration pattern (PubChem) |
|---|---|---|
| 3d (first row) | Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn | [Ar]4s2 3d1 to [Ar]4s2 3d10 |
| 4d (second row) | Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd | [Kr]5s2 4d1 to [Kr]5s2 4d10 |
| 5d (third row) | La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg | [Xe]6s2 5d1, then [Xe]6s2 4f14 5d2 onwards |
| 4f (lanthanoids) | Ce to Lu | [Xe]6s2 4f1 5d1 to [Xe]6s2 4f14 5d1 |
| 5f (actinoids) | Th to Lr | [Rn]7s2 6d2 to [Rn]7s2 5f14 6d1 |
Zinc, cadmium and mercury need a note. Their atoms end in a full d10 subshell, and PubChem lists +2 as the only common oxidation state for zinc and cadmium, so their usual ions keep that full d10 shell too. Your textbook therefore does not treat them as typical transition elements, even though they sit in the d block and PubChem files them under "transition metal". If a NEET option asks which d block element shows no transition behaviour, think of zinc first.
The first-row transition elements in numbers
The first row is where Unit 11 asks for trends, so this is the table to know. Configurations, first ionization energy, common oxidation states, melting point and density all come from PubChem.
| Element | Configuration | First ionization energy (eV) | Common oxidation states | Melting point (K) | Density (g/cm3) |
|---|---|---|---|---|---|
| Sc | [Ar]4s2 3d1 | 6.561 | +3 | 1,814 | 2.99 |
| Ti | [Ar]4s2 3d2 | 6.828 | +4, +3, +2 | 1,941 | 4.5 |
| V | [Ar]4s2 3d3 | 6.746 | +5, +4, +3, +2 | 2,183 | 6.0 |
| Cr | [Ar]3d5 4s1 | 6.767 | +6, +3, +2 | 2,180 | 7.15 |
| Mn | [Ar]4s2 3d5 | 7.434 | +7, +4, +3, +2 | 1,519 | 7.3 |
| Fe | [Ar]4s2 3d6 | 7.902 | +3, +2 | 1,811 | 7.874 |
| Co | [Ar]4s2 3d7 | 7.881 | +3, +2 | 1,768 | 8.86 |
| Ni | [Ar]4s2 3d8 | 7.640 | +3, +2 | 1,728 | 8.912 |
| Cu | [Ar]4s1 3d10 | 7.726 | +2, +1 | 1,357.77 | 8.933 |
| Zn | [Ar]4s2 3d10 | 9.394 | +2 | 692.68 | 7.134 |
Three patterns among these d and f block elements jump out, and each one is a classic question.
Why are chromium and copper exceptions?
Chromium is 3d5 4s1 instead of 3d4 4s2, and copper is 3d10 4s1 instead of 3d9 4s2. In both cases one electron moves from 4s into 3d so the d subshell ends up exactly half full (d5) or completely full (d10). Your textbook explains this as the extra stability of half-filled and filled subshells. Learn both exceptions by name, because an option that writes Cr as 3d4 4s2 is a deliberate trap.
Why does manganese show +7?
Count the electrons outside the argon core. Manganese has 4s2 3d5, seven in all, so losing or sharing all seven gives +7, the highest common state PubChem lists for any first-row element. The chart shows how the highest state climbs from scandium to manganese and then falls away.
From scandium to manganese, the highest state equals the number of 4s plus 3d electrons: 3, 4, 5, 6 and 7. After manganese the d electrons start to pair up and are held more tightly, so the highest common state drops. That rise and fall is the single most useful shape to remember for the first row of d and f block elements.
Why do zinc and manganese melt so low?
Melting points across the first row are high, around 1,700 to 2,200 K for most elements, with two clear dips. Manganese melts at 1,519 K and zinc at just 692.68 K. The usual textbook explanation is that metallic bonding in transition metals uses unpaired d electrons as well as s electrons, so melting points peak near the middle of the row. Zinc, with a full 3d10 subshell, has the weakest metallic bonding of the row.
Ionization energy, by contrast, barely moves for most of the row: 6.561 eV for scandium to 7.902 eV for iron in PubChem's data. That flat profile is itself a point worth knowing about the d and f block elements. Electrons are being added to an inner 3d subshell, which shields the outer 4s electrons fairly well, so each extra proton has a smaller effect than it would in the p block. Zinc's jump to 9.394 eV fits its stable, full 3d10 subshell.
The properties Unit 11 names, one by one
Unit 11 lists colour, catalytic behaviour, magnetic properties, complex formation, interstitial compounds and alloy formation. These properties of d and f block elements are explained in your textbook rather than in a data table, so learn each as one reason plus one example.
Magnetic properties. Among the d and f block elements, an ion with unpaired d electrons is paramagnetic. The spin-only formula, μ = √(n(n + 2)) BM, where n is the number of unpaired electrons, gives the values NEET options are built from. Worked out, that is 1.73 BM for one unpaired electron, 2.83 for two, 3.87 for three, 4.90 for four and 5.92 for five. Mn2+ (3d5, five unpaired) sits at the top; Zn2+ (3d10) has none and is diamagnetic.
Colour. Most transition metal ions are coloured because an electron can jump between d orbitals of slightly different energy, absorbing part of visible light. An ion with no d electrons (Sc3+, 3d0) or a full set (Zn2+, 3d10) has no such jump available, which is why your textbook describes both as colourless.
Catalytic behaviour. Many d and f block elements and their compounds act as catalysts because they can switch between oxidation states and offer surfaces where reactants bind. The variable oxidation states in the table above are the root of it.
Complex formation. Small, highly charged ions with vacant d orbitals bind ligands strongly. This is the bridge to Unit 12, coordination compounds, so revise the two units back to back.
Interstitial compounds and alloys. In the d and f block elements, small atoms such as hydrogen, carbon or nitrogen can sit in the gaps of a transition metal lattice, giving hard, high-melting interstitial compounds. Transition metals also mix readily with one another to form alloys, because their atomic sizes are similar.
What should you know about KMnO4 and K2Cr2O7?
These are the only compounds Unit 11 names, so they are the most predictable part of the d and f block elements. The syllabus asks for their preparation, properties and uses. PubChem's compound records give the facts below; the metal oxidation states are simple arithmetic on the formula.
| Potassium permanganate | Potassium dichromate | |
|---|---|---|
| Formula | KMnO4 | K2Cr2O7 |
| Molecular weight (PubChem) | 158.034 | 294.18 |
| Appearance (PubChem) | Dark purple or bronze-like crystals | Orange-red crystals |
| Oxidation state of the metal | Mn +7 (K is +1, four O are -8) | Cr +6 (two K are +2, seven O are -14, so 2Cr = +12) |
| Preparation route (PubChem) | Manganese dioxide heated with potassium hydroxide and an oxidant to give potassium manganate, which is then converted to permanganate electrolytically, or by treating the hot manganate solution with chlorine, air or carbon dioxide | Chrome ore roasted with potassium carbonate or potassium hydroxide, or sodium dichromate reacted with potassium chloride |
| Uses listed by PubChem | Water purification, bleaching, disinfectant and antiseptic, food processing, leather tanning | Dyeing, leather tanning, bleaching and oxidising, dry cell depolarizer |
Read the potassium permanganate and potassium dichromate records once if you like seeing the source. For the exam, three points matter most:
- Both are strong oxidising agents because the metal is in its highest common state (+7 for Mn, +6 for Cr), so it tends to be reduced.
- Both preparations go through an intermediate salt. Permanganate comes from manganate; dichromate comes from chromate or sodium dichromate. Writing the intermediate correctly is a common option trap.
- KMnO4 is also practical chemistry. Unit 20 lists "oxalic acid vs KMnO4" and "Mohr's salt vs KMnO4" titrations, so its colour change and its oxidising role carry into a second unit.
How do lanthanoids and actinoids differ?
Lanthanoids are the 4f series of d and f block elements, from cerium to lutetium, and they show +3 as the common oxidation state almost everywhere. Actinoids are the 5f series, from thorium to lawrencium, and several of them show many more states. PubChem's lists make the contrast clear.
| Series | Common oxidation states in PubChem | Members that break the +3 pattern |
|---|---|---|
| Lanthanoids (Ce to Lu, 14 elements) | +3 for every one | Ce also +4; Sm, Eu and Yb also +2 |
| Actinoids (Th to Lr, 14 elements) | +3 for most, but a wider spread overall | Th +4 only; Pa +5, +4; U, Np, Pu and Am each +6, +5, +4, +3; Bk also +4; Md and No also +2 |
Why do these two rows of d and f block elements differ? The 5f orbitals of the actinoids are less buried than the 4f orbitals of the lanthanoids, so more of their electrons can take part in bonding. That is the standard explanation, and it is the one line on actinoids that the syllabus most clearly sets you up to give.
Lanthanoid contraction is the steady decrease in atomic and ionic size from lanthanum to lutetium. Each step adds a proton and a 4f electron, but 4f electrons shield the outer electrons poorly, so the outer shell is pulled in a little each time. The big consequence for NEET: the second-row and third-row transition elements of the same group, such as zirconium and hafnium, end up almost the same size, which is why they are so alike in chemistry.
Which lines trap students in Unit 11?
Most errors on d and f block elements come from a short, predictable list.
- Thinking the d and f block elements were deleted. They were not. Unit 11 is in the current NMC syllabus file.
- Writing Cr as 3d4 4s2 or Cu as 3d9 4s2. The real configurations are 3d5 4s1 and 3d10 4s1.
- Removing 3d electrons before 4s when forming ions. For first-row ions the 4s electrons go first, so Fe2+ is 3d6 and Fe3+ is 3d5.
- Calling zinc a typical transition element. Its atom and its usual Zn2+ ion both have a full 3d10 subshell.
- Giving the highest first-row oxidation state to chromium. It is manganese, at +7.
- Mixing up colourless ions. Sc3+ (3d0) and Zn2+ (3d10) are the ones your textbook calls colourless.
- Saying all lanthanoids show only +3. Cerium also shows +4, and samarium, europium and ytterbium also show +2 in PubChem's list.
- Skipping the two named compounds. KMnO4 and K2Cr2O7 are the only compounds written into Unit 11, and KMnO4 returns in Unit 20.
How should you revise d and f block elements for NEET?
Revising d and f block elements rewards a fixed order more than long hours. A plan that fits into one week of normal study:
- Copy the scope onto one page. Write the Unit 11 lines, the Unit 9 periodicity line and the Unit 20 KMnO4 titrations and cations. That page is everything this topic can ask.
- Write the first row from memory. Sc to Zn with configurations, until Cr and Cu come out right every time. Check against the table above.
- Draw the two shapes. Sketch the oxidation state rise to manganese and the melting point dips at manganese and zinc without looking, then compare with the charts.
- Learn the property list as reasons. One reason and one example each for colour, magnetism, catalysis, complexes, interstitial compounds and alloys. Practise the spin-only values for one to five unpaired electrons.
- Make a two-column card for KMnO4 and K2Cr2O7: preparation, colour, oxidation state, uses. Turn every exception in this guide into a flashcard too; our guide to NEET flashcards shows how to set them up.
- Test under time. Do mixed inorganic questions and sort wrong answers by trap. A wrong answer at plus four and minus one costs five marks against a right one, which our NEET negative marking guide explains.
How many questions will the d and f block elements carry in 2027? Nobody can tell you honestly: NTA publishes the subject-wise pattern, not a chapter-wise split. What is fixed is the paper, 45 Chemistry questions for 180 marks. For a sensible view of where this unit sits in a revision order, futureMBBS's NEET 2027 chapter-wise weightage guide is a good next read, and the NEET syllabus overview on futureMBBS puts all three subjects on one page.
Revise this unit right after p block elements for NEET, because the periodic trends carry straight over, and keep chemical bonding for NEET close for the ideas behind complex formation. For the full subject plan, start with our NEET 2027 Chemistry preparation strategy; for practice by unit, see the NEET Chemistry questions guide. Our NEET previous year question papers guide shows how to use old papers without wasting them, and futureMBBS explains why NEET leans on the NCERT book and lays out how to prepare for NEET from start to finish.
Want to see whether the d and f block elements are costing you marks? NEETsheet's chapter-wise Chemistry sets and timed mocks show which trap you keep falling into, so your next revision goes there first. Start at neetsheet.in.
Sources
Every syllabus line and number above comes from these documents, opened and read on 29 October 2026.
- National Medical Commission (UGMEB), Syllabus for NEET (UG) 2026, public notice of 22 December 2025, linked from neet.nta.nic.in (Chemistry Units 9, 10, 11, 12 and 20): https://cdnbbsr.s3waas.gov.in/s37bc1ec1d9c3426357e69acd5bf320061/uploads/2026/01/202601081066816297.pdf
- National Testing Agency, Information Bulletin NEET (UG) 2026 (pattern: Chemistry 45 questions and 180 of 720 marks; plus four and minus one marking; syllabus FAQ stating no change for 2026): https://cdnbbsr.s3waas.gov.in/s37bc1ec1d9c3426357e69acd5bf320061/uploads/2026/02/202602231394640855.pdf
- National Testing Agency, NEET (UG) public notices, checked on 29 October 2026 for any NEET (UG) 2027 notice: https://neet.nta.nic.in/public-notices/
- PubChem, US National Library of Medicine, Periodic Table of Elements (electron configurations, first ionization energies in eV, common oxidation states, melting points, densities and element categories for the d and f block): https://pubchem.ncbi.nlm.nih.gov/periodic-table/
- PubChem, Potassium permanganate, CID 516875 (formula, molecular weight, colour, manufacturing methods, uses): https://pubchem.ncbi.nlm.nih.gov/compound/Potassium-permanganate
- PubChem, Potassium dichromate, CID 24502 (formula, molecular weight, colour, manufacturing methods, uses): https://pubchem.ncbi.nlm.nih.gov/compound/Potassium-dichromate
Frequently Asked Questions
Yes. The d and f block elements are Chemistry Unit 11 of the NMC syllabus for NEET (UG) 2026, the current file. The 2026 bulletin says the syllabus did not change from the previous year, and no 2027 syllabus had been published by 29 October 2026.
Zinc's atom is [Ar]4s2 3d10 and its only common oxidation state in PubChem is +2, so its usual ion keeps a full 3d10 subshell. With no partly filled d orbitals, it lacks the colour, paramagnetism and variable oxidation states of typical transition elements.
Manganese. Its configuration is [Ar]4s2 3d5, seven electrons outside the argon core, and PubChem lists +7 as its highest common oxidation state, as in KMnO4. Chromium comes next at +6, as in K2Cr2O7.
Lanthanoid contraction is the steady decrease in atomic and ionic size from lanthanum to lutetium. The added 4f electrons shield the outer electrons poorly, so the nucleus pulls them in a little more each step. As a result, zirconium and hafnium are almost the same size.
Nobody can say officially. NTA publishes the subject-wise pattern, 45 Chemistry questions for 180 marks in NEET (UG) 2026, but no chapter-wise split. Treat any fixed number online as an estimate, and revise Unit 11's configurations, trends and the two named compounds properly.
