Transition elements: electronic configuration occurrence and general trends, oxidation states and catalytic behaviour - Question Bank

1. The catalytic activity of a transition metal catalyst is often explained by:
A) Its high melting point
B) Its ability to form unstable intermediate compounds with reactants
C) Its inertness
D) Its large atomic volume
2. Which of the following transition metals is most abundant in the Earth's crust?
A) Iron (Fe)
B) Titanium (Ti)
C) Copper (Cu)
D) Chromium (Cr)
3. The oxidation state of Manganese in MnO₄⁻ is:
A) +2
B) +4
C) +6
D) +7
4. Which of the following is a key characteristic of transition elements that allows them to form alloys?
A) Their tendency to lose all valence electrons
B) Their similar atomic radii and crystal structures
C) Their high ionization energies
D) Their inert nature
5. The electronic configuration of Chromium (Cr) is:
A) [Ar] 3d⁴ 4s²
B) [Ar] 3d⁵ 4s¹
C) [Ar] 3d³ 4s²
D) [Ar] 3d⁶ 4s⁰
6. Which of the following is an example of a homogeneous catalyst involving a transition metal?
A) Ni in hydrogenation of oils
B) Pt in catalytic converters
C) Fe in Haber process
D) Rh complexes in hydroformylation
7. The relative stability of various oxidation states of transition metals is related to:
A) Their electronegativity
B) Their ionization energies
C) The stability of the resulting electronic configuration
D) Their atomic mass
8. The complex ion [Cu(NH₃)₄]²⁺ is blue. This colour is due to:
A) Charge transfer
B) d-d transitions
C) Ligand field effects
D) The presence of ammonia ligands
9. Which of the following transition metal ions is paramagnetic?
A) Zn²⁺
B) Cu⁺
C) Sc³⁺
D) Ti³⁺
10. The electronic configuration of Vanadium (V) is:
A) [Ar] 3d³ 4s²
B) [Ar] 3d⁴ 4s¹
C) [Ar] 3d⁵ 4s⁰
D) [Ar] 3d² 4s²
11. The term 'transition element' is generally applied to elements that have:
A) A completely filled d subshell in their ground state or ionic state
B) An incompletely filled d subshell in their ground state or ionic state
C) A completely filled f subshell
D) An incompletely filled p subshell
12. Which of the following is a common use of transition metals in alloys for increased strength and hardness?
A) Copper in bronze
B) Iron in steel
C) Nickel in stainless steel
D) All of the above
13. The highest oxidation state of Ruthenium (Ru) is:
A) +3
B) +4
C) +6
D) +8
14. The electronic configuration of Scandium (Sc) is:
A) [Ar] 3d¹ 4s²
B) [Ar] 3d² 4s¹
C) [Ar] 3d³
D) [Ar] 4s²
15. Transition metals form alloys because they have:
A) Similar atomic sizes and radii
B) Very different atomic sizes and radii
C) Low melting points
D) High reactivity
16. The colour of CuSO₄·5H₂O is blue due to the presence of:
A) Cu²⁺ ions
B) SO₄²⁻ ions
C) H₂O molecules
D) The crystal lattice
17. Which of the following is NOT an actinide element?
A) Thorium (Th)
B) Uranium (U)
C) Neptunium (Np)
D) Europium (Eu)
18. The reason for the small change in atomic radii across the second and third transition series is:
A) Increased shielding by d-electrons
B) Increased shielding by f-electrons
C) Lanthanoid contraction
D) Actinoid contraction
19. Which of the following transition metals is liquid at room temperature?
A) Iron (Fe)
B) Copper (Cu)
C) Mercury (Hg)
D) Silver (Ag)
20. The highest oxidation state observed in the first transition series is for:
A) Scandium (Sc)
B) Titanium (Ti)
C) Vanadium (V)
D) Manganese (Mn)
21. The element with electronic configuration [Ar] 3d⁵ 4s¹ is:
A) Chromium (Cr)
B) Manganese (Mn)
C) Iron (Fe)
D) Cobalt (Co)
22. Which of the following is a common use of transition metal compounds as pigments?
A) Titanium dioxide (TiO₂)
B) Iron oxides (Fe₂O₃)
C) Chromium oxides (Cr₂O₃)
D) All of the above
23. The density of transition elements generally:
A) Decreases across a period
B) Increases across a period
C) Remains constant across a period
D) Shows no definite trend across a period
24. Which of the following is the characteristic electronic configuration of Lanthanides?
A) ns² (n-1)d¹⁻¹⁰
B) ns² np⁶ (n-1)d¹⁻¹⁰ (n-2)f⁰⁻¹⁴
C) ns² np⁶ (n-1)d¹⁰
D) ns² np⁶ (n-1)d⁰⁻¹ (n-2)f¹⁻¹⁴
25. The catalytic activity of transition metals is enhanced by their ability to:
A) Increase the surface area of reactants
B) Lower the activation energy by forming intermediate compounds
C) Increase the temperature of the reaction
D) Decrease the concentration of reactants
26. Which of the following transition metal ions is colourless?
A) Cu⁺
B) V³⁺
C) Mn²⁺
D) Ni²⁺
27. The element with the electronic configuration [Xe] 4f¹⁴ 5d¹⁰ 6s² is:
A) Gadolinium (Gd)
B) Lutetium (Lu)
C) Ytterbium (Yb)
D) Thulium (Tm)
28. The magnetic behaviour of transition metals is generally:
A) Diamagnetic
B) Paramagnetic
C) Ferromagnetic
D) Antiferromagnetic
29. Which of the following is a common oxidation state for Iron (Fe)?
A) +1
B) +2 and +3
C) +4
D) +5
30. The general trend in ionization enthalpy across a period for transition elements is:
A) Irregular increase
B) Irregular decrease
C) Sharp increase
D) Sharp decrease
31. The electronic configuration of Copper (Cu) is [Ar] 3d¹⁰ 4s¹ due to:
A) Greater stability of a half-filled d subshell
B) Greater stability of a fully-filled d subshell
C) Lower ionization energy
D) Higher electron affinity
32. Which of the following is an example of a transition metal used as a catalyst in the hydrogenation of vegetable oils?
A) Iron (Fe)
B) Nickel (Ni)
C) Copper (Cu)
D) Cobalt (Co)
33. The colour of transition metal compounds is mainly due to:
A) d-d transitions
B) ns-np transitions
C) Interelectronic repulsion
D) Crystal field splitting
34. Which of the following transition metals has the highest melting point?
A) Iron (Fe)
B) Tungsten (W)
C) Copper (Cu)
D) Gold (Au)
35. The highest oxidation state exhibited by an element is often equal to:
A) The number of s electrons
B) The number of d electrons
C) The sum of s and d electrons in the valence shell
D) The number of p electrons
36. The oxidation state of Chromium in K₂Cr₂O₇ is:
A) +2
B) +3
C) +6
D) +7
37. Which of the following is a characteristic property of Actinides but not Lanthanides?
A) Formation of coloured ions
B) Paramagnetic nature
C) Radioactivity
D) Variable oxidation states
38. The trend in the atomic radii of transition elements across a period is generally:
A) Increases significantly
B) Decreases significantly
C) Remains almost constant
D) Increases then decreases
39. Which transition metal ion is responsible for the blue colour of the flame test in some cases?
A) Ni²⁺
B) Cu²⁺
C) Fe²⁺
D) Cr³⁺
40. The occurrence of transition elements in nature is primarily as:
A) Free elements
B) Oxides, sulfides, and carbonates
C) Noble gases
D) Alkaline earth metals
41. Which of the following is the most common oxidation state of Manganese (Mn)?
A) +2
B) +3
C) +4
D) +7
42. The catalytic activity of transition metals is attributed to:
A) Their high density
B) Their variable oxidation states and ability to form intermediate complexes
C) Their silvery appearance
D) Their low melting points
43. Which of the following transition metals commonly exhibits an oxidation state of +1?
A) Iron (Fe)
B) Copper (Cu)
C) Manganese (Mn)
D) Chromium (Cr)
44. The ability of transition metals to exhibit variable oxidation states is primarily due to:
A) Presence of only valence shell electrons
B) Involvement of both ns and (n-1)d electrons in bonding
C) Large ionization energies
D) Stable noble gas configurations
45. Which element is known for its variable oxidation states and is commonly used as a catalyst in the Haber process?
A) Iron (Fe)
B) Copper (Cu)
C) Nickel (Ni)
D) Manganese (Mn)
46. Lanthanides and Actinides belong to which block of the periodic table?
A) s-block
B) p-block
C) d-block
D) f-block
47. The general electronic configuration of inner transition elements (f-block) is:
A) ns¹⁻² (n-1)d¹⁻¹⁰
B) ns² np⁶ (n-1)d¹⁻¹⁰ (n-2)f¹⁻¹⁴
C) ns² np⁶ (n-1)d¹⁰
D) ns² (n-1)d¹
48. Which of the following is NOT a characteristic property of transition metals?
A) Formation of coloured compounds
B) Paramagnetic behaviour
C) High melting and boiling points
D) Tendency to form ionic compounds with very high lattice energy
49. Transition elements are found in which block of the periodic table?
A) s-block
B) p-block
C) d-block
D) f-block
50. Which of the following is the characteristic electronic configuration of transition elements?
A) ns¹⁻² (n-1)d¹⁻¹⁰
B) ns² np⁶
C) ns² (n-1)s²
D) ns² np⁶ (n-1)d¹⁰