Introduction to Transition Elements questions

The electron configuration of the last vertical column of the (d)-block elements is ..........

1. A ns² , nd¹⁰
2. B ns² , nd⁵
3. C ns² , (n−1)d¹⁰
4. D ns² , (n−1)d⁵

The elements that are most similar in properties are ..........

1. A Ni , Zn , Cu
2. B Cr , Mn , Fe
3. C Fe , Co , Ni
4. D Co , Ni , Cu

Which vertical group in the periodic table contains the largest number of elements?

1. A VB
2. B VIIB
3. C VIIIB
4. D VIII

Which of the following describes the elements whose electron configuration ends with the two sublevels ns² , (n−1)d³ ?

1. A They lie in the third column of the periodic table.
2. B They lie in group (VB).
3. C They lie in the tenth column of the periodic table.
4. D They lie in group (IIIB).

A transition metal that resists corrosion and is non-toxic, so it bonds well with bones.
What is the name of this metal?

1. A Nickel.
2. B Cobalt.
3. C Chromium.
4. D Titanium.

An element that is as hard as steel is ..........

1. A iron.
2. B zinc.
3. C titanium.
4. D nickel.

The opposite figure shows a part of the modern periodic table.
The distinguishing property of the alloy made of element (Y) and element (X) is ..........

1. A it has a low melting point.
2. B it has a high density.
3. C it is very hard.
4. D it cannot be shaped.

Which of the following substances is not used in making batteries?

1. A Cd
2. B MnO₂
3. C Co
4. D Sc

Each of the following shows the economic importance of some oxides of 3d elements, except ..........

1. A the rubber industry.
2. B detecting the positions of welded joints.
3. C a pigment in the ceramics industry.
4. D making the dry cell.

Each of the following is a compound of transition elements, except ..........

1. A the substance used to make pigments.
2. B the substance used in the paint industry.
3. C the surface of a piece of chromium exposed to weather conditions.
4. D the substance used as a catalyst in making magnets.

From the opposite equation : 4K₂Cr₂O₇ →(Δ) 4K₂CrO₄ + 3O₂ + 2X
Compound (X) is used in ..........

1. A making pigments.
2. B preserving food.
3. C the rubber industry.
4. D tanning leather.

The opposite figure shows a part of the modern periodic table of elements.
Which of the following describes element (M)?

1. A It lies in group 1B.
2. B It is used in coating metals to protect them from reduction.
3. C It looks like carbon.
4. D It can be magnetized.

H₂SO₄ can be kept in a container made of ..........

1. A iron.
2. B an alloy of (Sc , Al).
3. C cobalt-60.
4. D an alloy of (Ni , steel).

Each of the following describes the transition element (M) which lies in the first transition series and resists weather conditions, except ..........

1. A It lies in the fourth period of the periodic table.
2. B It is used in tanning leather.
3. C One of its compounds is used in making pigments.
4. D It is used in making soft-drink cans.

The opposite figure shows a part of the modern periodic table.
The two elements whose sulphates are each used to kill fungi are ..........

1. A (1) , (2)
2. B (2) , (3)
3. C (3) , (4)
4. D (2) , (4)

Each of the following describes a (d)-block element used to protect iron from rusting, except ..........

1. A It lies in group (IIB).
2. B Its oxide is used in the rubber industry.
3. C It lies in column (12) of the periodic table.
4. D It is used in making heating coils.

Two (d)-block elements (X) , (Y) are used in making one of the rechargeable batteries,
if element (Y) lies in the fifth period of the periodic table, then elements (X) , (Y) are ..........

1. A (X) : chromium , (Y) : cadmium.
2. B (X) : nickel , (Y) : cadmium.
3. C (X) : zinc , (Y) : yttrium.
4. D (X) : nickel , (Y) : zinc.

The two alloys (X) , (Y) have the following properties :
• Alloy (X) : strong and of low density.
• Alloy (Y) : heavy but resists corrosion.
Which of the following is a suitable use of each of the two alloys (X) , (Y)?

1. A (X) : aircraft , (Y) : spacecraft.
2. B (X) : railway lines , (Y) : aircraft.
3. C (X) : spacecraft , (Y) : bridge supports.
4. D (X) : bridge supports , (Y) : railway lines.

A transition element (A) whose oxide molecules are larger than its atoms, and an element (B) used in the hydrogenation of oils.
Which of the following is one of the uses of the alloy made of (A) , (B)?

1. A Electric furnaces.
2. B Car springs.
3. C MiG fighter aircraft.
4. D Spacecraft.

Element (A) is as hard as steel, and element (B) has scandium added to it to form an alloy that is light and very hard.
Which of the following is incorrect?

1. A Element (A) is non-toxic and lies in the fourth period.
2. B Alloys of element (B) with manganese resist corrosion.
3. C The strength of element (A) is greater than that of element (B) at high temperatures.
4. D The two elements (A , B) are elements of the first transition series.

For each of the following elements, the number of its group B in the periodic table can be found from the sum of the electrons in the two sublevels ns , (n−1)d in its electron configuration, except ..........

1. A ₂₁Sc
2. B ₂₈Ni
3. C ₂₅Mn
4. D ₂₃V

The oxidation numbers of the elements of the first transition series in their compounds range between ..........

1. A +1 : +7
2. B +2 : +8
3. C +2 : +7
4. D +3 : +7

Which of the following pairs of elements have more than one oxidation state in their compounds?

1. A Cr , Zn
2. B Sc , Cu
3. C Ti , Mn
4. D Zn , Co

Which of the following represents the electron configuration of an ion of one of the elements of the first transition series?

1. A [Ar] , 4s¹ , 3d¹⁰
2. B [Ar] , 4s¹ , 3d⁹
3. C [Ar] , 4s² , 3d⁸
4. D [Ar] , 3d¹⁰

The two oxidation states that most of the transition metals of the fourth period of the periodic table have in common are ..........

1. A +1 , +2
2. B +2 , +3
3. C +3 , +4
4. D +4 , +5

All the elements of the following groups have the oxidation state +2 , except the elements of group ..........

1. A VIIB
2. B VIB
3. C IIB
4. D IIIB

Which of the following ions has the largest number of unpaired electrons in its orbitals?

1. A Cu²⁺
2. B Fe²⁺
3. C Co⁴⁺
4. D Cr³⁺

The number of unpaired electrons in the cation of the compound CoCl₂ is ..........

1. A 2
2. B 3
3. C 4
4. D 5

When scandium reacts with :
• oxygen, it produces compound (X).
• chlorine, it produces compound (Y).
• dilute hydrochloric acid, it produces ion (Z).
Which of the following is correct?

1. A (X) : Sc₂O₃ , (Y) : ScCl₃ , (Z) : Sc³⁺(aq)
2. B (X) : Sc₂O₃ , (Y) : ScCl₂ , (Z) : Sc³⁺(aq)
3. C (X) : ScO , (Y) : ScCl₂ , (Z) : Sc²⁺(aq)
4. D (X) : ScO , (Y) : ScCl₃ , (Z) : Sc²⁺(aq)

The oxidation number of the cation of the compound used in making luminous paints is ..........

1. A +2
2. B +3
3. C +1
4. D +4

The 3d sublevel is half-filled in the two ions ..........

1. A Fe²⁺ , Mn³⁺
2. B Fe³⁺ , Mn²⁺
3. C Cr³⁺ , Mn²⁺
4. D Co²⁺ , Fe²⁺

If the electron configuration of the ion M³⁺ is [Ar] , 3d⁵ , then the atomic number of this transition element (M) is ..........

1. A 24
2. B 25
3. C 26
4. D 27

Which of the following shows the correct order of the following cations according to the number of unpaired electrons?

1. A Ti²⁺ < Cr³⁺ < Fe²⁺ < Mn²⁺
2. B Cr³⁺ < Ti²⁺ < Mn²⁺ < Fe²⁺
3. C Cr³⁺ < Fe²⁺ < Mn²⁺ < Ti²⁺
4. D Fe²⁺ < Ti²⁺ < Mn²⁺ < Cr³⁺

Which of the following describes the isotope of the transition element used to detect malignant tumours?

1. A It is used in making surgical instruments.
2. B Its atomic number is 60
3. C Its electron configuration : [Ar] , 4s¹ , 3d⁵
4. D Number of its unpaired electrons = 3

In which of the following pairs of groups of the periodic table do the elements differ in the number of unpaired electrons?

1. A 3 , 11
2. B 4 , 10
3. C 5 , 9
4. D 6 , 12

The opposite table shows ions of some elements of the first transition series.
Which of the following is used in modern car batteries?

1. A (W)
2. B (X)
3. C (Y)
4. D (Z)

Which of the following describes one of the (d)-block elements in the fourth period of the modern periodic table?

1. A Silver has the electron configuration : ns¹ , (n−1)d¹⁰
2. B Scandium has more than one oxidation state.
3. C The 3d sublevel is completely filled with electrons in the Cu⁺ ion
4. D There are 3 unpaired electrons in the Fe²⁺ ion

Which of the following ions have the electron configuration [Ar] , 3d⁶ ?

1. A Co²⁺ , Mn²⁺
2. B Cr³⁺ , Fe³⁺
3. C Mn³⁺ , Cr²⁺
4. D Co³⁺ , Fe²⁺

In which of the following cases is the manganese ion most stable?

1. A MnO₄²⁻
2. B Mn₂O₃
3. C Mn⁵⁺
4. D MnO

A metal (M) exists in the form of the following oxides and ions :
• MO₂ • M₂O₃ • HMO₄⁻ • MO₄⁻
Which of the following is the metal (M)?

1. A Chromium.
2. B Manganese.
3. C Iron.
4. D Cobalt.

The oxide of a transition element (MO) has 26 electrons in its cation.
Which metal follows element (M) in the same period of the periodic table?

1. A Co
2. B Ni
3. C Cu
4. D Zn

The compound MXY₄ is used as an insecticide and a fungicide.
What are the oxidation numbers of each of (M) , (X) , (Y) in this compound?

1. A (M) : +3 , (X) : +5 , (Y) : −2
2. B (M) : +2 , (X) : +6 , (Y) : −2
3. C (M) : +2 , (X) : +6 , (Y) : −8
4. D (M) : +1 , (X) : +7 , (Y) : −2

From the following table, which of the following is correct?

1. A MnO₂ : the oxidation number of manganese in it is +4 , KMnO₄ : used to disinfect water , MnSO₄ : is one of the alloys of manganese.
2. B MnO₂ : used to reduce H₂SO₄ , KMnO₄ : the oxidation number of manganese in it is +7 , MnSO₄ : used as a drier for inks.
3. C MnO₂ : reacts with Al forming Mn , Al₂O₃ , KMnO₄ : used to detect malignant tumours , MnSO₄ : the oxidation number of manganese in it is +2.
4. D MnO₂ : the oxidation number of manganese in it is +4 , KMnO₄ : added to fish tanks to fight parasites , MnSO₄ : protects crops from fungi.

Among the properties of the metal (M), which lies in the first transition series, are that :
• it is as hard as steel but less dense than it.
• its stable chloride is MCl₄
• it reacts with water according to the equation : M(s) + 2H₂O(v) →(Δ) MO₂(s) + 2H₂(g)
Another property of this metal is that it is ..........

1. A brittle in the pure state.
2. B toxic to the human body.
3. C stronger than aluminium at high temperatures.
4. D a strong oxidizing agent.

The ion of the metal (M) in the compound MO₂ has 3 electrons in the 3d sublevel
What is the formula of the sulphate of the metal (M) in which 3d has 5 electrons, and what is this compound used for?

1. A M(SO₄)₂ / an oxidizing agent.
2. B MSO₄ / making the dry cell.
3. C M(SO₄)₂ / an insecticide.
4. D MSO₄ / a fungicide.

The transition metal (M) used in tanning leather has something in common with the first metal known to man, which is ..........

1. A the ability to form the metal chloride MCl₃
2. B the number of electrons in the 4s sublevel
3. C its use in making fungicides.
4. D the number of electrons in the 3d sublevel

The metals of the first transition series react with halogens.
Which of the following represents the most stable metal halides?

1. A FeCl₃ , VBr₃ , TiCl₂
2. B MnBr₃ , VCl₄ , TiCl₄
3. C FeCl₃ , VF₅ , TiCl₄
4. D FeCl₂ , VCl₅ , TiBr₃

What is the chemical formula of yttrium sulphide?

1. A Y₃S₂
2. B YS
3. C Y₂S₃
4. D YS₃

Nanoparticles of the oxide of the transition metal (M) can stop ultraviolet rays from reaching the skin.
Each of the following is a possible oxidation of this metal and its ions, except ..........

1. A M → M²⁺
2. B M²⁺ → M⁴⁺
3. C M → M³⁺
4. D M³⁺ → M⁵⁺

The transition metal (M) that can be magnetized does not give an oxidation state whose electron configuration is ..........

1. A d⁵
2. B d⁶
3. C d⁷
4. D d¹

In the reaction : 2KMnO₄ + 16HCl → 5Cl₂ + 2MnCl₂ + 2KCl + 8H₂O
A reduction process is indicated by the formation of ..........

1. A Cl₂
2. B MnCl₂
3. C H₂O
4. D KCl

The two compounds KXO₄ , K₂XO₄ can change into each other.
What is the oxidation number of the transition element (X) in the oxidizing agent and in the reducing agent of them, respectively?

1. A +7 , +6
2. B +5 , +6
3. C +7 , +7
4. D +5 , +7

The following compounds can act as an oxidizing agent or a reducing agent in chemical reactions, except ..........

1. A FeO
2. B MnO
3. C Sc₂O₃
4. D Cr₂O₃

Which metal has an oxide with the chemical formula M₂O₃ that is used in making pigments?

1. A V
2. B Ti
3. C Cr
4. D Mn

The metal (M), which lies in the fourth period and group 3B of the periodic table, reacts with sulphuric acid, forming hydrogen and a salt whose chemical formula is ..........

1. A MSO₄
2. B M₂(SO₄)₃
3. C M(SO₄)₃
4. D M₃(SO₄)₂

Which of the following represents the electron configuration of a non-transition element?

1. A ns² , (n−1)d⁵
2. B ns² , (n−1)d¹⁰
3. C ns¹ , (n−1)d⁵
4. D ns¹ , (n−1)d¹⁰

Which of the following groups of elements includes only one main transition element?

1. A Ni , Co , Fe
2. B Cd , Ag , Cu
3. C Zn , Ti , Mn
4. D Y , Th , Hg

The largest ionization potential of a transition metal that has two unpaired electrons in the (n−1)d sublevel is the ..........

1. A second ionization potential.
2. B third ionization potential.
3. C fourth ionization potential.
4. D fifth ionization potential.

From the opposite graph :
Each of the following is correct, except ..........

1. A The second ionization potential of copper is greater than the second ionization potential of the other elements of the first transition series.
2. B The second ionization potential of chromium is greater than the second ionization potential of manganese.
3. C The first ionization potential of the elements of the first transition series increases by a large difference as their atomic numbers increase.
4. D The third ionization potential of manganese is greater than the first ionization potential of scandium.

From the opposite graph :
the ionization potential (X) represents the ..........

1. A fifth ionization potential.
2. B fourth ionization potential.
3. C third ionization potential.
4. D second ionization potential.

The opposite graph shows the trend of the two ionization energies (X) , (Y) for some metals of the first transition series.
Which of the following is correct?

1. A (X) : first ionization potential , (Y) : second ionization potential.
2. B (X) : second ionization potential , (Y) : third ionization potential.
3. C (X) : third ionization potential , (Y) : fourth ionization potential.
4. D (X) : fourth ionization potential , (Y) : fifth ionization potential.

The opposite graph shows the ionization potentials of the metal ..........

1. A titanium.
2. B chromium.
3. C iron.
4. D vanadium.

The opposite graph shows the ionization potentials of a transition element whose electron configuration is ..........

1. A [Ar] , 4s¹ , 3d⁵
2. B [Ar] , 4s² , 3d⁵
3. C [Ar] , 4s² , 3d⁶
4. D [Ar] , 4s¹ , 3d¹⁰

The following table shows the first four ionization potentials of one of the transition elements (M) :
The oxidation state of element (M) in which an electron was removed from a complete main energy level is ..........

1. A M⁺
2. B M²⁺
3. C M³⁺
4. D M⁴⁺

The following table shows the ionization potentials of four transition elements in (kJ/mol) :
Which of the previous elements has one of its compounds used as a catalyst in making superconducting magnets?

1. A (W)
2. B (X)
3. C (Y)
4. D (Z)

The transition element (X) has 12 radioactive isotopes :
(1) Determine the group of element (X) in the periodic table.
(2) Write the chemical formula of the sulphide of element (X) whose cation has 3 unpaired electrons.

The metal (Y) lies in the fifth period and group 3B of the periodic table :
(1) What is the electron configuration of the metal (X) that precedes it in the same group?
(2) What are the properties of the alloy of element (X) with aluminium?

One of the compounds of manganese is Mn₃(PO₄)₂ :
(1) Write the electron configuration of the manganese ion in this compound.
(2) Is the cation of this compound easy or difficult to oxidize? Explain.

The transition metal (M) combines with chlorine forming the compound MCl₂ , and the cation of this compound has 24 electrons :
(1) What is the name of the metal (M)?
(2) Write the electron configuration of this metal in its most stable oxidation state.

From the electron configuration of the two highest-energy sublevels of chromium, copper and zinc, determine :
(1) the similarity between copper and zinc.
(2) the difference between copper and chromium.

The compound MSO₄ is used as an insecticide and a fungicide :
(1) Write the electron configuration of the ion of the metal (M) in this compound.
(2) Why is the second ionization potential of this metal greater than its first ionization potential?

The opposite graph shows the ionization potentials of the metal (M), which lies in the first transition series :
(1) How many sublevels are completely filled with electrons in the stable ion of this metal?
(2) Write the chemical formula of the oxide of this metal and state its importance.

The two cations X³⁺ , Y²⁺ have the same electron configuration [Ar] , 3d⁴ :
(1) What is the name of each of the two metals (X) , (Y)?
(2) Write the chemical formulas of the compounds of (X) , (Y) that always act as oxidizing agents.

When sulphur dioxide gas is passed into a solution containing the permanganate ion, the violet colour of the solution disappears, and the reaction is shown by the following ionic equation :
5SO₂ + 2MnO₄⁻ + 2H₂O → 5SO₄²⁻ + 2Mn²⁺ + 4H⁺
From this reaction, deduce a property that shows that manganese is a transition element, and explain the role of MnO₄⁻ in this reaction.

An element of the first transition series, one of whose compounds is used in pigments.
Which of the following choices shows the electron configuration of the ion of this element in this compound?
(Sample exam 2026)

1. A [₁₈Ar] , 4s¹ , 3d⁵
2. B [₁₈Ar] , 3d³
3. C [₁₈Ar] , 4s² , 3d³
4. D [₁₈Ar] , 3d²

Which of the following shows the electron configuration of an ion of a non-transition element?
(Sample exam 2026)

1. A X³⁺ : [Ne] , 3s² , 3p⁶
2. B Y²⁺ : [Ar] , 3d⁶
3. C Z²⁺ : [Ne] , 3s² , 3p⁶
4. D W³⁺ : [Kr] , 4d⁷

Four test tubes (X) , (Y) , (Z) , (W) each contain a salt solution as in the following table : (X) : Mn(NO₃)₂ , (Y) : Fe(NO₃)₃ , (Z) : Ti(NO₃)₃ , (W) : V(NO₃)₅
Which of these tubes must be covered so that the composition of the solution inside it does not change?
(Sample exam 2026)

1. A X
2. B Y
3. C Z
4. D W

Which of the following shows the electron configuration of an ion of a transition element and a use of one of the compounds of this ion?
(Sample exam 2026)

1. A [₁₈Ar] , 3d³ / in the dry car battery.
2. B [₁₈Ar] / a catalyst in the contact process.
3. C [₁₈Ar] / in artificial joints.
4. D [₁₈Ar] , 3d⁶ / in the hydrogenation of oils.

Element (X) of the first transition series has its (d) sublevel complete with electrons.
Which of the following shows the type of the element and the electron configuration of the ion of this element in the compound X₂O ?
(Sample exam 2026)

1. A transition , [Ar] , 3d¹⁰
2. B transition , [Ar] , 3d⁹
3. C non-transition , [Ar] , 3d¹⁰
4. D non-transition , [Ar] , 3d⁹

Element (X) is one of the elements of the first transition series; its (d) sublevel is complete with electrons, and it has no unpaired electrons in any oxidation state.
Which of the following shows the type of the element and the electron configuration of the ion of this element in the compound XO ?
(Sample exam 2026)

1. A transition , [Ar] , 3d¹⁰
2. B transition , [Ar] , 3d⁹
3. C non-transition , [Ar] , 3d¹⁰
4. D non-transition , [Ar] , 3d⁹

Two elements (A) , (B) of the first transition series; the +2 ion of each of them contains four unpaired electrons, and element (A) is less dense than element (B).
Which of the following shows a use of each of (A) , (B)?
(Sample exam 2026)

1. A (A) : in making soft-drink cans , (B) : in reinforced concrete.
2. B (A) : in coating metals to protect them from rusting , (B) : in heating coils.
3. C (A) : in tanning leather , (B) : in making surgical instruments.
4. D (A) : in making pigments , (B) : a catalyst in making ammonia.

Three successive elements (A) , (B) , (C) of the first transition series; element (C) has twice the number of unpaired electrons in (B) and three times the number in element (A).
Which of the following shows the uses of the elements (A) , (B) , (C)?
(Sample exam 2026)

1. A (A) : the dry cell , (B) : coating metals , (C) : the composition of Fehling's solution
2. B (A) : hydrogenation of oils , (B) : heating coils , (C) : luminous paints
3. C (A) : an oxidizing and disinfecting substance , (B) : galvanization , (C) : making magnets
4. D (A) : artificial joints , (B) : making car springs , (C) : coating metals

Element (X) is one of the elements of the second transition series, and its electron configuration ends with ns⁽ⁿ⁻³⁾ , (n−1)d²ⁿ
Which of the following shows the type of element (X) and its use?
(Sample exam 2026)

1. A Transition, and used in making coins.
2. B Transition, and used with a non-transition element in making rechargeable batteries.
3. C Non-transition, and used with a transition element in making rechargeable batteries.
4. D Non-transition, and its oxide is used in making rubber and paints.

A main transition element (X) whose (d) sublevel has two unpaired electrons in the oxidation state (+3).
Which of the following oxidation states results in breaking a main energy level complete with electrons for this element?
(Sample exam 2026)

1. A X⁷⁺
2. B X⁶⁺
3. C X⁵⁺
4. D X⁴⁺

A transition element (X) of the first transition series; the number of unpaired electrons in its (d) sublevel is twice the number of unpaired electrons in copper.
Each of the following is a use of element (X), except ..........
(Sample exam 2026)

1. A coating metals to protect them from corrosion.
2. B a catalyst in changing vegetable oils into artificial ghee.
3. C it forms with chromium an alloy that resists corrosion.
4. D it forms with aluminium an alloy used in making MiG aircraft.

Which of the transition element ions in the following compounds is the easiest to reduce?
(Sample exam 2026)

1. A Mn(NO₃)₃
2. B Fe(NO₃)₃
3. C Ti(NO₃)₄
4. D V(NO₃)₅

The opposite graph shows the number of unpaired electrons in the oxidation state (+3) for elements of the first transition series,
Which of the following processes happens most easily?
(Sample exam 2026)

1. A M³⁺ ⟶ M⁴⁺
2. B X³⁺ ⟶ X²⁺
3. C Z³⁺ ⟶ Z²⁺
4. D W³⁺ ⟶ W²⁺

(X) , (Y) , (Z) are three transition elements used in medicine :
(X) : one of its alloys is used in surgical instruments.
(Y) : used in artificial joints.
(Z) : one of its isotopes is used in diagnosing and treating malignant tumours.
Which of the following shows the elements (X) , (Y) , (Z)?
(Sample exam 2026)

1. A (X) : chromium , (Y) : cobalt , (Z) : cadmium
2. B (X) : iron , (Y) : titanium , (Z) : cobalt
3. C (X) : cobalt , (Y) : vanadium , (Z) : chromium
4. D (X) : iron , (Y) : titanium , (Z) : vanadium

The following table shows the electron configuration of the cations of two elements (X) , (Y) : X²⁺ : [₁₈Ar] , 3d⁴ , Y²⁺ : [₁₈Ar] , 3d²
Which of the following is correct?
(Sample exam 2026)

1. A X⁶⁺ is difficult to oxidize to X⁷⁺
2. B Y²⁺ is difficult to oxidize to Y⁴⁺
3. C X⁶⁺ is easily reduced to X²⁺
4. D Y⁴⁺ is easily reduced to Y³⁺

Element (X) of the first transition series is used in an acid-resistant alloy.
Which of the following represents the electron configuration of the ion X³⁺ ?
(Sample exam 2026)

1. A [₁₈Ar] , 3d³
2. B [₁₈Ar] , 3d⁶
3. C [₁₈Ar] , 3d⁷
4. D [₁₈Ar] , 3d⁴

Which of the following processes represents the most difficult change?
(1st session 2025)

1. A From titanium (III) to titanium (IV).
2. B From vanadium (IV) to vanadium (V).
3. C From iron (III) to iron (II).
4. D From manganese (IV) to manganese (II).

The ratio between the number of unpaired electrons in element (A), used as a catalyst in making ammonia, and that in element (B), used as a catalyst in the hydrogenation of oils, equals ..........
(Sample exam 2025)

1. A (A) : 2 , (B) : 1
2. B (A) : 1 , (B) : 2
3. C (A) : 3 , (B) : 1
4. D (A) : 1 , (B) : 3

If (A) , (B) are two successive elements in the first transition series, and element (B) is the last element that can lose all of its (4s , 3d) electrons, then the ionization potential of element (A) that can break a complete energy level is the ..........
(Sample exam 2025)

1. A ninth.
2. B seventh.
3. C eighth.
4. D tenth.

(X , Y , Z) are three successive transition elements in the first transition series, and element (X) is used in making rechargeable batteries.
Which of the following shows the electron configuration of the ions of these elements in the following oxides XO₂ – Y₂O₃ – ZO ?
(Sample exam 2025)

1. A XO₂ : 3d⁶ , Y₂O₃ : 3d⁶ , ZO : 3d⁶
2. B XO₂ : 3d⁸ , Y₂O₃ : 3d⁶ , ZO : 3d⁸
3. C XO₂ : 3d⁶ , Y₂O₃ : 3d⁸ , ZO : 3d⁶
4. D XO₂ : 3d⁸ , Y₂O₃ : 3d⁸ , ZO : 3d⁶

An element (X) of the first transition series whose M level contains twice the number of electrons in the L level
Which of the following is correct for this element?
(Sample exam 2025)

1. A It reacts instantly with acids.
2. B It forms with chromium an alloy with a low melting point.
3. C It is used with cadmium in making rechargeable batteries.
4. D A catalyst in obtaining car petrol from water gas.

Two successive elements (X) , (Y) of the first transition series, where :
• (X) : is easily oxidized from X²⁺ ⟶ X³⁺
• (Y) : is easily oxidized from Y³⁺ ⟶ Y⁴⁺
then the two elements are ..........
(2nd session 2024)

1. A (X) : titanium , (Y) : vanadium.
2. B (X) : vanadium , (Y) : chromium.
3. C (X) : cobalt , (Y) : nickel.
4. D (X) : iron , (Y) : cobalt.

Two elements (A) , (B) of the first transition series; element (A) has two unpaired electrons in the d sublevel, and the d sublevel of element (B) is half-filled.
The alloy made of them is used in ..........
(2nd session 2024)

1. A heating coils.
2. B railway rails.
3. C soft-drink cans.
4. D making dry batteries.

Two elements (X) , (Y) whose cations have the electron configurations :
X⁴⁺ : [₁₈Ar] , 3d¹
Y⁶⁺ : [₁₈Ar] , 3d²
One of the advantages of the alloy made of element (X) with one of the alloys of element (Y) with carbon is that it ..........
(Trial exam / March 2023)

1. A is light and very hard.
2. B resists corrosion and is hard.
3. C resists corrosion at high temperatures.
4. D keeps its strength at high temperatures.

A transition element (X) that lies in the fourth period and has the highest possible oxidation state in it can form all the following compounds except ..........
(Trial exam / June 2021)

1. A XCl
2. B XCl₂
3. C XCl₃
4. D XCl₄

Element (X) is one of the elements of the first transition series, and the electron configuration of one of its ions is [₁₈Ar] , 3d⁵
then the element is ..........
(2nd session 2021)

1. A Zn
2. B V
3. C Sc
4. D Fe

The electron configuration of the ion (X³⁺) is [₁₈Ar] , 3d⁶ , so element (X) is used in ..........
(2nd session 2022)

1. A car springs.
2. B dry batteries.
3. C a fungicide.
4. D the hydrogenation of oils.

The electron configuration of the ion of the transition element (X) in the compound X₂O₃ has three unpaired electrons,
then the element lies in the periodic table in group number ..........
(1st session 2021)

1. A 9
2. B 10
3. C 11
4. D 12

The transition element used in the hydrogenation of oils has the electron configuration of its ion M³⁺ ..........
(1st session 2021)

1. A [₁₈Ar] , 3d⁷
2. B [₁₈Ar] , 3d⁸
3. C [₁₈Ar] , 4s² , 3d⁷
4. D [₁₈Ar] , 4s² , 3d⁸

Element (X) is one of the coinage metals and is a transition element, and the compounds that prove this are ..........
(Trial exam / June 2021)

1. A X₂O₃ , XO
2. B XCl , XO
3. C X₂O₃ , X₂O
4. D X₂O₃ , XCl

Two elements (X) , (Y) of the first transition series, each of which has a compound used as a fungicide,
then the two elements lie in the groups ..........
(1st session 2022)

1. A 1B , 7B
2. B 1B , 2B
3. C 3B , 2B
4. D 2B , 7B

The opposite graph shows the relation between the atomic number of three successive transition elements X , Y , Z and some of their oxidation numbers.
The groups in which they probably lie are ..........
(Trial exam / June 2021)

1. A X : VIB , Y : VIIB , Z : VIII
2. B X : IB , Y : IIB , Z : IIIB
3. C X : IVB , Y : VB , Z : BIV
4. D X : IIIB , Y : VIB , Z : VB

Based on the atomic numbers and the possible oxidation states of the following elements : (₂₅Mn , ₁₇Cl , ₂₂Ti , ₂₈Ni)
Which of the following is correct?
(1st session 2022)

1. A FeCl₃ is difficult to obtain from FeCl₂
2. B MnCl₂ is easily obtained from MnCl₃
3. C NiCl₇ is easily obtained
4. D TiCl₄ is difficult to obtain

If the electron configurations of the cations of some transition elements are :
A²⁺ : [₁₈Ar] , 3d³ , B²⁺ : [₁₈Ar] , 3d⁵
Which of the following processes happens easily?
(1st session 2023)

1. A Reduction of (B⁷⁺) to (B³⁺).
2. B Reduction of (A⁵⁺) to (A³⁺).
3. C Oxidation of (B²⁺) to (B³⁺).
4. D Oxidation of (A³⁺) to (A⁵⁺).

Which of the following transition elements has the largest first ionization potential?
(Trial exam / June 2021)

1. A Ni ⟶ Ni⁺
2. B V ⟶ V⁺
3. C Sc ⟶ Sc⁺
4. D Ti ⟶ Ti⁺

A main transition element, one of whose oxidation states, X³⁺ , makes the d sublevel contain 2 electrons.
The ionization potential of the element is very high in the oxidation state ..........
(Trial exam / June 2021)

1. A X⁶⁺
2. B X³⁺
3. C X⁵⁺
4. D X⁴⁺

You have the following compounds : KMnO₄ , K₂MnO₄ , MnO₂
It is easy to obtain ..........
(2nd session 2023)

1. A K₂MnO₄ from KMnO₄ by oxidation.
2. B KMnO₄ from K₂MnO₄ by oxidation.
3. C MnO₂ from KMnO₄ by reduction.
4. D K₂MnO₄ from MnO₂ by reduction.