Q.1 Which of the following is a characteristic property of transition elements?
They form only ionic compounds
They show variable oxidation states
They do not form colored compounds
They have low melting points
Explanation - Transition elements are known for their ability to exhibit multiple oxidation states, unlike s- and p-block elements.
Correct answer is: They show variable oxidation states
Q.2 Which of the following elements is considered a first-row transition element?
Scandium
Tin
Zinc
Calcium
Explanation - First-row transition elements are those with partially filled d-orbitals in the 3d series. Scandium (Sc) is one of them.
Correct answer is: Scandium
Q.3 Which transition metal exhibits a +2 oxidation state in all its compounds?
Copper
Zinc
Chromium
Manganese
Explanation - Zinc has a completely filled d10 configuration and typically forms only +2 oxidation state compounds.
Correct answer is: Zinc
Q.4 Which of the following elements forms a colored ion in solution?
Titanium
Calcium
Magnesium
Sodium
Explanation - Transition metals often form colored ions due to d-d electron transitions. Titanium ions are colored in aqueous solution.
Correct answer is: Titanium
Q.5 Which of the following pairs of elements have the same number of unpaired electrons in their ground state?
Cr and Mn
Fe and Co
Ti and V
Ni and Cu
Explanation - Titanium (3d2) has 2 unpaired electrons and Vanadium (3d3) has 3 unpaired electrons. Only Ti and V have comparable unpaired electrons for similar chemical behavior.
Correct answer is: Ti and V
Q.6 Which of the following elements is used in making stainless steel?
Chromium
Copper
Zinc
Silver
Explanation - Chromium is added to steel to make it corrosion-resistant, forming stainless steel.
Correct answer is: Chromium
Q.7 Which of the following is a characteristic magnetic property of transition elements?
All are diamagnetic
All are paramagnetic
Some are paramagnetic due to unpaired electrons
None show magnetic behavior
Explanation - Transition metals with unpaired d electrons are paramagnetic, while those with completely filled d orbitals are diamagnetic.
Correct answer is: Some are paramagnetic due to unpaired electrons
Q.8 Which transition element exhibits the highest number of oxidation states?
Manganese
Iron
Copper
Zinc
Explanation - Manganese can exhibit oxidation states from +2 to +7, showing the highest range among first-row transition elements.
Correct answer is: Manganese
Q.9 Which of the following is true about the catalytic property of transition elements?
Only 3d metals are catalysts
They act as catalysts due to variable oxidation states
They never act as catalysts
They act as catalysts because they are highly reactive metals
Explanation - Transition elements act as catalysts because they can change oxidation states and form intermediate complexes easily.
Correct answer is: They act as catalysts due to variable oxidation states
Q.10 Which of the following elements does not form a stable +3 oxidation state?
Scandium
Copper
Iron
Cobalt
Explanation - Copper commonly forms +1 and +2 oxidation states, but +3 is highly unstable.
Correct answer is: Copper
Q.11 Which of the following compounds shows a magnetic moment of zero?
[Zn(H2O)6]2+
[Fe(H2O)6]3+
[Mn(H2O)6]2+
[Cu(H2O)4]2+
Explanation - Zinc(II) has a d10 configuration with no unpaired electrons, so it is diamagnetic.
Correct answer is: [Zn(H2O)6]2+
Q.12 Which of the following is a characteristic property of the transition metal ions?
They all have filled d-orbitals
They form complex ions
They are highly reactive with water
They never form alloys
Explanation - Transition metals form complex ions due to their vacant d-orbitals which can accept lone pairs from ligands.
Correct answer is: They form complex ions
Q.13 Which of the following is the correct electron configuration of Cr?
[Ar] 3d4 4s2
[Ar] 3d5 4s1
[Ar] 3d6 4s0
[Ar] 3d3 4s1
Explanation - Chromium is an exception to the aufbau principle to achieve a half-filled stable 3d5 configuration.
Correct answer is: [Ar] 3d5 4s1
Q.14 Which of the following elements shows the maximum number of oxidation states in the first transition series?
Titanium
Manganese
Iron
Nickel
Explanation - Manganese shows oxidation states from +2 to +7, the widest range in the first transition series.
Correct answer is: Manganese
Q.15 Which of the following elements forms the most stable complex with ammonia?
Copper
Zinc
Calcium
Sodium
Explanation - Copper(II) forms stable complexes like [Cu(NH3)4]2+ due to coordination with ligands.
Correct answer is: Copper
Q.16 Which of the following elements is least likely to exhibit multiple oxidation states?
Scandium
Iron
Manganese
Copper
Explanation - Scandium commonly forms only +3 oxidation state due to its 3d1 4s2 configuration.
Correct answer is: Scandium
Q.17 Which of the following ions is colored in solution due to d-d transitions?
[Ti(H2O)6]3+
[Zn(H2O)4]2+
[Ca(H2O)6]2+
[Na(H2O)6]+
Explanation - Titanium(III) ion has unpaired d electrons which undergo d-d transitions, giving color.
Correct answer is: [Ti(H2O)6]3+
Q.18 Which of the following elements is used as a catalyst in the Haber process?
Iron
Copper
Zinc
Nickel
Explanation - Iron acts as a catalyst in the Haber process for the production of ammonia.
Correct answer is: Iron
Q.19 Which of the following transition metals forms a stable +6 oxidation state?
Chromium
Copper
Zinc
Manganese
Explanation - Chromium forms CrO3 and other compounds in +6 oxidation state.
Correct answer is: Chromium
Q.20 Which of the following transition elements shows the lowest first ionization energy?
Copper
Zinc
Scandium
Manganese
Explanation - Among first-row transition metals, copper has lower ionization energy due to filled 3d10 4s1 configuration.
Correct answer is: Copper
Q.21 Which of the following elements forms both +1 and +2 oxidation states?
Copper
Manganese
Chromium
Iron
Explanation - Copper exhibits +1 (Cu+) and +2 (Cu2+) oxidation states commonly.
Correct answer is: Copper
Q.22 Which of the following is true about the density of transition metals?
They have very low densities
They have high densities and high melting points
They are all gases at room temperature
They are all brittle
Explanation - Transition metals have strong metallic bonding, leading to high densities and melting points.
Correct answer is: They have high densities and high melting points
Q.23 Which of the following metals is liquid at room temperature?
Mercury
Copper
Iron
Nickel
Explanation - Mercury is the only metal among transition elements that is liquid at room temperature.
Correct answer is: Mercury
Q.24 Which of the following elements exhibits the maximum number of oxidation states in the second transition series?
Molybdenum
Ruthenium
Tungsten
Technetium
Explanation - Molybdenum shows multiple oxidation states ranging from +2 to +6, typical for second transition series elements.
Correct answer is: Molybdenum
Q.25 Which of the following transition metals is used in catalytic converters?
Platinum
Iron
Copper
Zinc
Explanation - Platinum acts as a catalyst in catalytic converters to reduce vehicle emissions.
Correct answer is: Platinum