NEET Class 12 Chemistry MCQs – d- and f-Block Elements

The d- and f-Block Elements – MCQs (NEET Style)

Q1. Which of the following is a characteristic feature of transition elements?
A. High ionization enthalpy
B. Variable oxidation states
C. Low melting points
D. Non-metallic nature

Q2. The general electronic configuration of d-block elements is:
A. (n-1)d¹⁻¹⁰ ns²
B. (n-1)d³⁻⁵ ns²
C. ns² np⁶
D. ns² np¹

Q3. Which element shows the highest number of oxidation states in its compounds?
A. Sc
B. Mn
C. Fe
D. Zn

Q4. The color of most transition metal ions is due to:
A. Ionization of metal
B. d-d electronic transitions
C. s-p transitions
D. Nuclear spin

Q5. Which of the following metals is diamagnetic?
A. Fe²⁺
B. Cu⁺
C. Mn²⁺
D. Cr³⁺

Q6. Which property increases across the d-block from left to right?
A. Metallic character
B. Atomic radius
C. Ionization enthalpy
D. Reactivity with acids

Q7. The highest oxidation state of chromium is:
A. +2
B. +3
C. +6
D. +4

Q8. Which transition element exhibits +2 oxidation state predominantly?
A. Fe
B. Zn
C. Mn
D. Ti

Q9. The element which shows no variable oxidation state is:
A. Zn
B. Fe
C. Mn
D. Cu

Q10. Which of the following acts as a good catalyst in the Haber process?
A. Fe
B. Ni
C. Cu
D. Zn

Q11. The paramagnetic character of a transition metal is due to:
A. Unpaired d-electrons
B. Paired d-electrons
C. s-electrons
D. p-electrons

Q12. Which of the following is a strong oxidizing agent?
A. KMnO₄
B. Na₂O
C. ZnO
D. Cr₂O₃

Q13. The reaction Fe²⁺ → Fe³⁺ + e⁻ is an example of:
A. Reduction
B. Oxidation
C. Neutralization
D. Precipitation

Q14. Which of the following forms colored ions in aqueous solution?
A. Alkali metals
B. Alkaline earth metals
C. Transition metals
D. Noble gases

Q15. Among the first-row transition metals, which has the highest melting point?
A. Sc
B. Fe
C. Cr
D. Zn

Q16. The lanthanide contraction is due to:
A. Poor shielding of 4f electrons
B. Large nuclear size
C. High reactivity
D. d-electron contraction

Q17. Which element has [Xe]4f⁷6s² configuration?
A. Gd
B. Sm
C. Eu
D. Ce

Q18. Actinides are mostly:
A. Non-metals
B. Metals
C. Metalloids
D. Noble gases

Q19. The common oxidation state of lanthanides is:
A. +2
B. +3
C. +4
D. +5

Q20. The most stable oxidation state of uranium is:
A. +2
B. +3
C. +4
D. +6

Q21. Which of the following is a typical f-block element?
A. Ce
B. Ti
C. Cu
D. Zn

Q22. The electronic configuration of Mn³⁺ is:
A. [Ar]3d⁵
B. [Ar]3d⁴
C. [Ar]3d³
D. [Ar]3d⁶

Q23. Which transition metal shows +1 oxidation state commonly?
A. Cu
B. Fe
C. Cr
D. Mn

Q24. Which of the following is a commonly used ligand in coordination compounds?
A. NH₃
B. H₂O
C. Cl⁻
D. All of the above

Q25. The compound K₂Cr₂O₇ is:
A. Reducing agent
B. Oxidizing agent
C. Neutral
D. Colorless

Q26. The color of KMnO₄ in solution is:
A. Green
B. Violet
C. Blue
D. Colorless

Q27. Which transition metal is used in catalytic converters?
A. Pt
B. Zn
C. Ti
D. Sc

Q28. Which element has the lowest melting point among first-row transition metals?
A. Fe
B. Zn
C. Cr
D. Co

Q29. Which of the following shows variable oxidation states in its compounds?
A. Sc
B. Ti
C. Cu
D. Zn

Q30. The f-block elements are called:
A. Inner transition elements
B. Outer transition elements
C. Noble gases
D. Post-transition metals

Q31. The element which shows +2 and +3 oxidation states commonly:
A. Fe
B. Zn
C. Sc
D. Cu

Q32. The radioactive actinide used in nuclear reactors is:
A. Uranium
B. Cerium
C. Lanthanum
D. Neodymium

Q33. The oxidation state of Ce in CeO₂ is:
A. +2
B. +3
C. +4
D. +6

Q34. Which of the following is not a transition metal?
A. Zn
B. Cr
C. Fe
D. Ni

Q35. The formation of complex ion involves:
A. Ionic bonding
B. Covalent bonding
C. Coordinate covalent bonding
D. Metallic bonding

Q36. The most stable oxidation state of Cr is:
A. +2
B. +3
C. +4
D. +6

Q37. Which element shows magnetic properties?
A. Fe
B. Zn
C. Cd
D. Hg

Q38. Lanthanides exhibit:
A. Large size variation
B. Small size variation
C. Lanthanide contraction
D. Both B and C

Q39. Which element is used in fluorescent lamps?
A. Eu
B. Ce
C. Tb
D. Nd

Q40. Which metal forms colored salts due to d-d transition?
A. Fe³⁺
B. Zn²⁺
C. Na⁺
D. K⁺

Q41. The melting point of transition metals generally:
A. Decreases across the period
B. Increases across the period
C. Is irregular
D. Zero

Q42. Which element is used in stainless steel?
A. Cr
B. Mn
C. Fe
D. Ni

Q43. The number of f-electrons in Gd³⁺ is:
A. 5
B. 7
C. 8
D. 9

Q44. Actinides differ from lanthanides because they:
A. Have variable oxidation states
B. Are radioactive
C. Both A and B
D. Neither A nor B

Q45. The element which shows +2, +3 and +4 oxidation states is:
A. Ce
B. Nd
C. Sm
D. Gd

Q46. Which of the following is a strong reducing agent?
A. V²⁺
B. Fe³⁺
C. MnO₄⁻
D. Cr₂O₇²⁻

Q47. The complex [Fe(CN)₆]³⁻ is:
A. Hexacyanoferrate(III)
B. Hexacyanoferrate(II)
C. Hexaaquairon(III)
D. Hexaaquairon(II)

Q48. The oxidation state of Mn in KMnO₄ is:
A. +6
B. +7
C. +2
D. +4

Q49. Which of the following is used in nuclear reactors as fuel?
A. Uranium
B. Cerium
C. Gadolinium
D. Lanthanum

Q50. The color of Cr₂O₇²⁻ ions in solution is:
A. Orange
B. Green
C. Blue
D. Colorless

Q51. Which transition metal shows catalytic property in H₂ + I₂ → 2HI?
A. Pt
B. Ni
C. Fe
D. Zn

Q52. The actinide which shows +6 oxidation state commonly is:
A. Uranium
B. Thorium
C. Plutonium
D. Neptunium

Q53. The element which exhibits lanthanide contraction is:
A. Lanthanides
B. Actinides
C. d-block elements
D. Alkali metals

Q54. The ion [Co(NH₃)₆]³⁺ is:
A. Octahedral
B. Tetrahedral
C. Square planar
D. Linear

Q55. The d-block element forming KMnO₄ is:
A. Mn
B. Fe
C. Cr
D. Cu

Q1. B – Transition elements show variable oxidation states.
Q2. A – General configuration: (n–1)d¹⁻¹⁰ ns².
Q3. B – Mn shows oxidation states from +2 to +7.
Q4. B – Color arises from d-d electronic transitions.
Q5. B – Cu⁺ has completely filled d¹⁰ configuration → diamagnetic.
Q6. C – Ionization enthalpy increases across the d-block due to increasing nuclear charge.
Q7. C – Chromium exhibits +6 in compounds like CrO₃, K₂Cr₂O₇.
Q8. B – Zn mostly shows +2; others have variable oxidation states.
Q9. A – Zn has filled d¹⁰, shows only +2.
Q10. A – Fe acts as catalyst in Haber process.
Q11. A – Unpaired d-electrons give paramagnetism.
Q12. A – KMnO₄ is a strong oxidizing agent.
Q13. B – Loss of electron = oxidation.
Q14. C – Transition metals form colored ions due to d-d transitions.
Q15. C – Cr has highest melting point among first-row transition metals.
Q16. A – Poor shielding by 4f electrons causes lanthanide contraction.
Q17. A – Gadolinium (Gd): [Xe]4f⁷6s².
Q18. B – Actinides are metals.
Q19. B – Lanthanides mostly exhibit +3 oxidation state.
Q20. D – Uranium’s common stable oxidation state in compounds is +6 (e.g., UO₂²⁺).
Q21. A – Ce is an f-block element (lanthanide).
Q22. B – Mn³⁺: [Ar]3d⁴.
Q23. A – Copper commonly shows +1 oxidation state.
Q24. D – All listed species are common ligands.
Q25. B – K₂Cr₂O₇ is an oxidizing agent.
Q26. B – KMnO₄ is violet in solution.
Q27. A – Pt is used in catalytic converters.
Q28. B – Zn has the lowest melting point among first-row transition metals.
Q29. B – Ti exhibits variable oxidation states.
Q30. A – f-block elements are inner transition elements.
Q31. A – Fe commonly shows +2 and +3.
Q32. A – Uranium is used as nuclear reactor fuel.
Q33. C – Ce in CeO₂ is +4.
Q34. A – Zn is not a transition metal (d¹⁰ configuration).
Q35. C – Complexes involve coordinate covalent bonding.
Q36. B – +3 is the most stable state of Cr.
Q37. A – Fe is magnetic due to unpaired d-electrons.
Q38. D – Lanthanides show lanthanide contraction and small size variation.
Q39. A – Eu is used in fluorescent lamps.
Q40. A – Fe³⁺ forms colored salts due to d-d transitions.
Q41. C – Transition metals show irregular melting points.
Q42. A – Chromium is added to steel to make stainless steel.
Q43. B – Gd³⁺ has 7 f-electrons.
Q44. C – Actinides are radioactive and show variable oxidation states.
Q45. A – Cerium shows +2, +3, +4 oxidation states.
Q46. A – V²⁺ is a strong reducing agent.
Q47. A – [Fe(CN)₆]³⁻ is hexacyanoferrate(III).
Q48. B – Mn in KMnO₄ is +7.
Q49. A – Uranium is nuclear fuel.
Q50. A – Cr₂O₇²⁻ is orange in solution.
Q51. A – Pt catalyzes H₂ + I₂ → 2HI.
Q52. A – Uranium commonly shows +6 oxidation state.
Q53. A – Lanthanides exhibit lanthanide contraction.
Q54. A – [Co(NH₃)₆]³⁺ has octahedral geometry.
Q55. A – KMnO₄ is a manganese compound.

Disclaimer:

All MCQs and solutions are educational, and for practice purposes only. They are based on NCERT and NEET syllabus and are not official NEET questions.