The d- and f-Block ElementsNEET MCQs with solutions
The d- and f-Block Elements covers transition metals (3d series), their electronic configurations, oxidation states, magnetic properties, interstitial compounds, alloy formation and important compounds (KMnO₄, K₂Cr₂O₇). Lanthanoids and actinoids are also covered. NEET tests specific properties, exceptions in electronic configuration, and reactions of KMnO₄ and K₂Cr₂O₇.
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Practise 24 questions
Tap an option to check it. Questions from every NCERT topic in this chapter, from easy to hard.
Q1Important PYQ Mixed Concepts
An atom with electronic configuration [Ar]3d3 4s2 belongs to which group of the periodic table?
Not quite — the answer is B.
The configuration [Ar]3d3 4s2 corresponds to vanadium (Z=23). The group number equals the total valence electrons in 3d and 4s: 3+2=5. Therefore vanadium belongs to Group 5. Group 3 has a different d-electron count; Group 2 has no d-electrons; Group 15 is a main-group element.
Q2Important PYQ Mixed Concepts
Among Cr, Fe, Mn and V, which element exhibits the maximum number of oxidation states?
Not quite — the answer is C.
Manganese (Mn) exhibits the widest range of oxidation states (+2 to +7) among these elements because all 3d and 4s electrons can participate in bonding. Cr reaches up to +6, V up to +5, and Fe commonly +3. Mn alone attains +7 in KMnO4.
Q3Mixed Revision
Which of the following is an interstitial compound?
Not quite — the answer is A.
TiC is formed when small carbon atoms occupy interstitial sites in the titanium lattice. Transition metals readily form interstitial compounds with small atoms such as H, B, C and N. NaCl, K2O and CaCl2 are ionic compounds.
Q4Mixed Revision
Which property is mainly responsible for the high enthalpies of atomisation in transition metals?
Not quite — the answer is B.
Strong metallic bonding in transition metals results from participation of both ns and (n-1)d electrons. This gives them high enthalpies of atomisation compared to s-block metals.
Q5Grand Test
Which of the following electronic configurations represents the ground-state atom of chromium?
Not quite — the answer is B.
Chromium adopts the exceptional [Ar]3d5 4s1 configuration because the half-filled 3d5 arrangement provides additional stability. The expected [Ar]3d4 4s2 configuration is less stable by comparison. The other options are not valid ground-state configurations for chromium.
Q6Grand Test
Which of the following ions is colourless due to a d0 electronic configuration?
Not quite — the answer is C.
Sc3+ has the [Ar]3d0 configuration, making ordinary d-d transitions impossible and rendering it colourless. Ti3+ is 3d1, Fe2+ is 3d6 and Cu2+ is 3d9; all have partially filled d-subshells and can show colour.
Q7The Lanthanoids
Which is the general electronic configuration of lanthanoids?
Not quite — the answer is A.
Lanthanoids (Ce to Lu) follow [Xe] 4f¹⁻¹⁴ 5d⁰⁻¹ 6s² configuration. Option B is the actinoid configuration. Options C and D are 3d and 4d transition series configurations respectively.
Q8The Lanthanoids
Which is the most common oxidation state shown by lanthanoids?
Not quite — the answer is B.
Lanthanoids predominantly show +3 oxidation state formed by losing two 6s and one 5d (or 4f) electron. This is the most stable state across the entire series. +4 and +2 are shown only by a few exceptions.
Q9General Introduction and Electronic Configuration
Which block elements are characterized by the filling of d orbitals in their electronic configuration?
Not quite — the answer is C.
d-block elements are defined by progressive filling of (n-1)d orbitals. This distinguishes them from s-block (ns filling), p-block (np filling), and f-block (nf filling) elements. Their position in the periodic table between s- and p-blocks reflects this orbital filling sequence.
Q10General Introduction and Electronic Configuration
Which is the correct general electronic configuration of d-block elements?
Not quite — the answer is A.
d-block elements have (n-1)d¹⁻¹⁰ ns⁰⁻² configuration; the ns⁰ case is critical — Pd (4d¹⁰ 5s⁰) is a real example. Option D is tempting but restricts ns to only ns², which is incorrect.
Q11Occurrence and Extraction of Transition Metals
Which of the following transition metals commonly occurs in native (free) state?
Not quite — the answer is A.
Cu, Ag, and Au occur in native/free state due to low reactivity and position low in the electrochemical series. Fe, Zn, and Mn are highly reactive and always found as compound ores. Option B is tempting as iron is abundant but it occurs as haematite/magnetite.
Q12Occurrence and Extraction of Transition Metals
Which method is used for concentration of sulphide ores?
Not quite — the answer is B.
Froth flotation exploits the difference in wettability between sulphide ore particles (wetted by oil) and gangue (wetted by water). Leaching is used for oxide/carbonate ores. Calcination and roasting are pyrometallurgical steps, not concentration steps.
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Get RankUp on Google PlayQ13General Properties of Transition Elements
Which element shows the maximum number of oxidation states in the 3d series?
Not quite — the answer is C.
Mn shows oxidation states from +2 to +7 due to the maximum number of unpaired d-electrons (d⁵ in Mn²⁺), allowing maximum involvement of electrons in bonding. Sc is limited to +3 (no d-electrons after ionisation) and Zn is limited to +2 (d¹⁰).
Q14General Properties of Transition Elements
Which of the following ions is colourless in aqueous solution?
Not quite — the answer is D.
Sc³⁺ has configuration [Ar] 3d⁰ — no d-electrons means no d-d transition is possible, so no visible light is absorbed and the ion appears colourless. Ti³⁺ (d¹), Fe³⁺ (d⁵), and Ni²⁺ (d⁸) all have d-electrons and show colour.
Q15Some Important Compounds of Transition Elements
Which of the following is the strongest oxidizing agent in acidic medium among these options?
Not quite — the answer is A.
KMnO4 with Mn in +7 state is a stronger oxidizer than K2Cr2O7 (Cr +6) in acidic medium; it gains 5e- per Mn atom vs 3e- per Cr atom, making it more powerful. FeSO4 and CuSO4 are not significant oxidizers under standard conditions.
Q16Some Important Compounds of Transition Elements
Which compound forms green manganate ion (MnO4 2-) in alkaline medium?
Not quite — the answer is B.
In alkaline medium, KMnO4 (MnO4-, purple) is reduced to MnO4 2- (manganate ion), which is green. K2Cr2O7 and K2CrO4 are chromium compounds; FeCl3 forms Fe(OH)3 in alkaline medium.
Q17The Actinoids
Which is the most common oxidation state exhibited by actinoids?
Not quite — the answer is B.
+3 is the most common oxidation state of actinoids, similar to lanthanoids. However, unlike lanthanoids, actinoids also commonly show +4, +5, +6 due to comparable 5f, 6d, 7s energies.
Q18The Actinoids
Which actinoid most commonly exhibits the highest stable oxidation state of +6?
Not quite — the answer is B.
Uranium most commonly and stably shows +6 (e.g., UO₂²⁺, UF₆). While Np and Pu can reach +7, +6 is not their most stable state. Thorium is most stable at +4 and rarely exceeds it.
Q19Applications of d and f Block Elements
Which transition metal acts as a catalyst in the Haber process for industrial synthesis of ammonia?
Not quite — the answer is B.
Iron (Fe) is the catalyst in the Haber process (N₂ + 3H₂ → 2NH₃). Ni catalyses hydrogenation reactions. V₂O₅ is the catalyst in the Contact process for H₂SO₄. Cu has no role here.
Q20Applications of d and f Block Elements
Which of the following correctly states the composition of stainless steel?
Not quite — the answer is A.
Stainless steel contains iron alloyed with chromium (~18%) and nickel (~8%). Chromium provides corrosion resistance by forming a passive Cr₂O₃ layer; nickel improves toughness. Option B and C are incorrect alloy combinations not classified as stainless steel.
Q21Revision Boost
Which of the following ions is colourless due to absence of d electrons?
Not quite — the answer is C.
Sc³⁺ has configuration [Ar] 3d⁰ — no d electrons, hence no d-d transitions possible, making it colourless. Ti³⁺ (3d¹), Fe²⁺ (3d⁶), and Ni²⁺ (3d⁸) all have partially filled d orbitals and form coloured ions.
Q22Revision Boost
Which of the following transition metal ions has the maximum number of unpaired electrons?
Not quite — the answer is B.
Mn²⁺ has configuration [Ar] 3d⁵ — five unpaired electrons (one in each d orbital). Fe²⁺ is 3d⁶ (4 unpaired), Co²⁺ is 3d⁷ (3 unpaired), Ni²⁺ is 3d⁸ (2 unpaired). Half-filled d⁵ gives maximum unpaired electrons.
Q23General Introduction and Electronic Configuration
Which of the following correctly explains why d-block elements are called transition elements?
Not quite — the answer is B.
IUPAC defines transition elements as those with partially filled d orbitals in ground state or common oxidation states — but the name "transition" refers to their periodic table position bridging s- and p-blocks. Option A is a common misconception; option C and D describe properties, not the reason for the name.
Q24General Introduction and Electronic Configuration
Which of the following is NOT considered a transition element as per IUPAC definition?
Not quite — the answer is D.
IUPAC defines transition elements as those having partially filled d orbitals in the ground state or in any stable oxidation state. Zn has 3d¹⁰ 4s² ground state and its only stable ion Zn²⁺ is also 3d¹⁰ — fully filled throughout. Fe, Cr, and Mn all form ions with partially filled d orbitals.
ELITE question · AIR under 50 level
This chapter has 230 ELITE questions for students aiming at the very top. They are only in the app.
Unlock ELITE questions in the appKey d-Block Facts
Quick revision: most questions in this chapter test these facts.
| Property / Compound | Key Fact |
|---|---|
| Electronic config exceptions | Cr = [Ar]3d⁵4s¹ (not 3d⁴4s²); Cu = [Ar]3d¹⁰4s¹ (not 3d⁹4s²) — stability of half/fully filled d |
| Variable oxidation states | Due to small energy difference between 3d and 4s; Mn shows +2 to +7 |
| Magnetic properties | Paramagnetic if unpaired electrons; μ = √(n(n+2)) BM |
| KMnO₄ | Strong oxidising agent; purple colour; self-indicator in titrations |
| K₂Cr₂O₇ | Orange (Cr₂O₇²⁻) in acid, yellow (CrO₄²⁻) in base; oxidising agent |
| Lanthanoid contraction | Gradual decrease in size across 4f series; poor shielding by 4f electrons |
What the app covers in this chapter
524 questions in total, each with a detailed explanation.
| Important PYQ Mixed Concepts | 97 |
| Mixed Revision | 74 |
| Grand Test | 55 |
| The Lanthanoids | 41 |
| General Introduction and Electronic Configuration | 40 |
| Occurrence and Extraction of Transition Metals | 40 |
| General Properties of Transition Elements | 40 |
| Some Important Compounds of Transition Elements | 40 |
| The Actinoids | 39 |
| Applications of d and f Block Elements | 39 |
| Revision Boost | 19 |
Questions students ask
Is d- and f-Block important for NEET?
Yes — electronic configuration exceptions (Cr, Cu), oxidation states, magnetic properties and reactions of KMnO₄ and K₂Cr₂O₇ are tested every year.
Which topics should I revise first?
Focus on electronic configuration exceptions, variable oxidation states across 3d series, magnetic moment formula, preparation and properties of KMnO₄ and K₂Cr₂O₇, and lanthanoid contraction.
How many questions from this chapter are on RankUp?
The RankUp app has 524 questions on The d- and f-Block Elements, including 230 ELITE questions. Every question has a detailed explanation.
