General Properties of the First Transition Series questions

As the atomic number of the transition elements in the same period increases ..........

1. A the ionization energy decreases.
2. B the radius increases.
3. C the density decreases.
4. D oxidation becomes more difficult.

Two elements (X) , (Y) of the first transition series, each with its 4s sublevel half-filled with electrons, and element (X) comes before element (Y).
Which of the following is incorrect?

1. A The atomic radius of element (X) = the atomic radius of element (Y).
2. B The number of electrons in the (3d) sublevel of element (Y) is twice that of element (X).
3. C The oxidation states of the two elements (X , Y) do not exceed the group number of each of them.
4. D The two elements (X , Y) are more electronically stable in the atomic state.

Four transition elements of the first series (A , B , C , D) :
• (A) : smallest atomic radius.
• (B) : highest boiling point.
• (C) : highest density.
• (D) : highest melting point.
What is the correct order of the four elements according to the effective nuclear charge?

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

Two elements (X) , (Y) of the first transition series have the same number of unpaired electrons in the oxidation state (+2).
If (X) can be magnetized, then ..........

1. A the density of (Y) is greater than that of (X).
2. B the atomic mass of (Y) is greater than that of (X).
3. C the atomic radius of (X) is greater than that of (Y).
4. D the effective nuclear charge of element (X) is greater than that of (Y).

The following figure shows a part of the periodic table :
Each of the following is correct, except ..........

1. A The atomic mass of element (4) is greater than that of element (3).
2. B The melting point of element (1) is greater than that of element (3).
3. C The atomic radii of elements (1) , (2) are equal.
4. D The density of element (2) is less than that of element (3).

The atoms of the transition element used in tanning leather have something in common with the atoms of the transition element added to aluminium to make the alloy used in making soft-drink cans, which is ..........

1. A the number of unpaired electrons.
2. B the number of electrons in the (d) sublevel.
3. C the melting point.
4. D the number of oxidation states.

The opposite table shows the atomic radii of four successive elements of the first transition series.
Which of these elements has the highest density?

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

What is the similarity between scandium and zinc?

1. A Both are used in galvanizing steel.
2. B Each of them has only one oxidation state.
3. C Their densities are close.
4. D They have the same atomic size.

From the following graphs :
Which of the following shows the property shown by each of figures (1) , (2) , (3), respectively?

1. A (1) : atomic radius , (2) : effective nuclear charge , (3) : atomic mass.
2. B (1) : atomic mass , (2) : effective nuclear charge , (3) : atomic radius.
3. C (1) : atomic radius , (2) : atomic mass , (3) : effective nuclear charge.
4. D (1) : effective nuclear charge , (2) : atomic radius , (3) : atomic mass.

The metal (A) lies in the fourth period of the periodic table :
• it reacts with silicon forming the compound A₂Si
• it is used in making magnets.
• its atomic radius is the same as the atomic radius of the metal (B).
then the two metals (A) , (B) are ..........

1. A (A) : Fe , (B) : Ni
2. B (A) : Cu , (B) : Ni
3. C (A) : Co , (B) : Cu
4. D (A) : Co , (B) : Fe

What is the correct order of the density of the following metals?

1. A Sc < V < Ni < Co
2. B Sc < V < Co < Ni
3. C Sc < Ni < Co < V
4. D Co < Ni < V < Sc

From the following statements :
• Metal (1) : used as a catalyst in making ammonia gas.
• Metal (2) : one of its compounds is used in making Fehling's solution.
• Metal (3) : used in tanning leather.
• Metal (4) : used in making mercury vapour lamps.
The least chemically active of these metals is ..........

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

Which of the following describes the transition element (M), a solution of one of whose compounds is used to detect glucose?

1. A Very chemically active.
2. B Of limited chemical activity.
3. C Smaller in radius than the element before it in the period.
4. D Higher in melting point than the element before it in the period.

Which of the following shows the properties of a transition element?

1. A Density : 0.97 g/cm³ , melting point : 98°C
2. B Density : 2.64 g/cm³ , melting point : 769°C
3. C Density : 3.1 g/cm³ , melting point : −7°C
4. D Density : 8.96 g/cm³ , melting point : 1085°C

The opposite graph is for some elements of the first transition series and their cations.
Which of the following is correct?

1. A The melting point of metal (X) is less than that of metal (Z).
2. B The atomic mass of metal (Y) is greater than that of metal (Z).
3. C The atomic mass of metal (X) is greater than that of metal (Y).
4. D Metal (Y) has more than one oxidation state, while metal (Z) has only one oxidation state.

Which of the following describes the properties of vanadium metal and of V₂O₅, respectively?

1. A Its density is greater than 5 g/cm³ / coloured.
2. B Its density is greater than 5 g/cm³ / colourless.
3. C Its density is less than 1 g/cm³ / coloured.
4. D Its density is less than 1 g/cm³ / colourless.

Which of the following shows the comparison between scandium and iron?

1. A Fourth ionization potential : scandium greater and iron less , reaction with water : scandium faster and iron slower
2. B Fourth ionization potential : scandium greater and iron less , reaction with water : scandium slower and iron faster
3. C Fourth ionization potential : scandium less and iron greater , reaction with water : scandium faster and iron slower
4. D Fourth ionization potential : scandium less and iron greater , reaction with water : scandium slower and iron faster

Three transition metals of the elements of the first transition series :
• Metal (X) : its density is the greatest compared with the other elements of the series.
• Metal (Y) : the number of its known oxidation states is 4.
• Metal (Z) : its melting point is the greatest compared with the other elements of the series.
These elements are arranged in increasing order of effective nuclear charge as follows ..........

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

Each of the following describes the properties of transition metals, except ..........

1. A Their melting and boiling points are high.
2. B They have lustre and shine.
3. C They form ionic compounds.
4. D Most of them do not give the oxidation state +2

The compound CuNO₃ is ..........

1. A paramagnetic and its cation is Cu⁺
2. B paramagnetic and its cation is Cu²⁺
3. C diamagnetic and its cation is Cu⁺
4. D diamagnetic and its cation is Cu²⁺

Which of the following pairs of compounds are paramagnetic?

1. A ScCl₃ , Zn(NO₃)₂
2. B ZnCl₂ , CrCl₃
3. C Co(NO₃)₂ , CrCl₃
4. D Co(NO₃)₂ , ScCl₃

Which of the following ions is a diamagnetic ion?

1. A Ti⁴⁺
2. B Mn²⁺
3. C Fe²⁺
4. D V²⁺

The following compounds are repelled by an external magnetic field, except ..........

1. A Sc₂(SO₄)₃
2. B CuF₂
3. C ZnSO₄
4. D CuCl

Which of the following metals and its ion are repelled by an external magnetic field?

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

From the opposite figure :
The cation of substance (X) may be ..........

1. A Ni²⁺(aq) , Zn²⁺(aq)
2. B Cu⁺(aq) , Cr³⁺(aq)
3. C Ni²⁺(aq) , Cr³⁺(aq)
4. D Cu⁺(aq) , V³⁺(aq)

Each of the following shows the trend of the properties of some transition elements and their ions, except ..........

1. A Number of unpaired electrons : Fe³⁺ > Mn³⁺ > Sc³⁺
2. B Magnetic moment : Mn²⁺ < Ni²⁺ < Co²⁺ < Fe²⁺
3. C Chemical activity : Sc > Fe > Cu
4. D Number of possible oxidation states : Sc < Ti < V < Mn

The solutions of which of the following substances increase in apparent weight when placed in an external magnetic field?

1. A TiO₂
2. B Fe₂(SO₄)₃
3. C KMnO₄
4. D ScCl₃

• Statement (1) : Zn²⁺ is a diamagnetic substance.
• Statement (2) : Zn loses two electrons from the 3d sublevel forming the ion Zn²⁺
Which of the following describes each of the two statements (1) , (2)?

1. A Statement (1) is correct and statement (2) is wrong.
2. B Statement (1) is wrong and statement (2) is correct.
3. C Statement (1) is correct and statement (2) is correct.
4. D Statement (1) is wrong and statement (2) is wrong.

Which of the following shows the trend of the magnetic moment of the following ions?

1. A V⁴⁺ < Ni²⁺ < Mn⁴⁺ < Fe³⁺
2. B Mn⁴⁺ < V⁴⁺ < Ni²⁺ < Fe³⁺
3. C V⁴⁺ < Ni²⁺ < Fe³⁺ < Mn⁴⁺
4. D Fe³⁺ < Mn⁴⁺ < Ni²⁺ < V⁴⁺

Which of the following shows the trend of the paramagnetic property of the following ions?

1. A Ti²⁺ > Mn²⁺ > Cr²⁺ > V²⁺
2. B Mn²⁺ > Cr²⁺ > V²⁺ > Ti²⁺
3. C V²⁺ > Ti²⁺ > Mn²⁺ > Cr²⁺
4. D Mn²⁺ > Cr²⁺ > Ti²⁺ > V²⁺

The opposite table shows the group numbers of three metals of the first transition series :
(X) : group (IIB) , (Y) : group (IVB) , (Z) : group (IB)
What is the correct order of the ions of these metals according to their magnetic moment?

1. A X²⁺ < Y²⁺ < Z²⁺
2. B Z²⁺ < X²⁺ < Y²⁺
3. C Y²⁺ < X²⁺ < Z²⁺
4. D X²⁺ < Z²⁺ < Y²⁺

The metal (X) comes directly before the metal (Y) in the first transition series, both have the same atomic radius, and one salt of each of them is used as an oxidizing agent.
Which of the following describes the two oxides X₂O₃ , Y₂O₃ ?

1. A X₂O₃ is paramagnetic , Y₂O₃ is diamagnetic.
2. B The magnetic moment of the compound X₂O₃ is greater than that of the compound Y₂O₃
3. C The apparent weight of each of X₂O₃ , Y₂O₃ increases when placed in a magnetic field.
4. D The apparent weight of X₂O₃ decreases and the apparent weight of Y₂O₃ increases when placed in an external magnetic field.

From the two opposite figures :
Which of the following shows the cations of each of the two substances (1) , (2)?

1. A (1) : Fe²⁺ , (2) : Zn²⁺
2. B (1) : Fe²⁺ , (2) : Cu⁺
3. C (1) : Zn²⁺ , (2) : Cu⁺
4. D (1) : Zn²⁺ , (2) : Fe²⁺

Each of the following describes transition elements, except ..........

1. A that all their ions are paramagnetic.
2. B that they are good conductors of heat and electricity.
3. C that the (d) sublevel is filled successively in them.
4. D that they lie between the (s) and (p) blocks.

All the following ions are diamagnetic, except ..........

1. A ₂₇Co²⁺
2. B ₃₀Zn²⁺
3. C ₄₇Ag⁺
4. D ₄₈Cd²⁺

The magnetic moment of a transition metal is as large as possible when its d sublevel contains ..........

1. A 2 electrons.
2. B 5 electrons.
3. C 7 electrons.
4. D 9 electrons.

The magnetic moment μ of the atoms of elements and their ions is measured in BM and is found from the relation : μ = √(n(n+2)) , where n is the number of unpaired electrons.
Which of the following ions has a magnetic moment of 5.9 BM ?

1. A Fe²⁺
2. B Fe³⁺
3. C Ni²⁺
4. D Cu²⁺

A transition element (A) of the first series whose highest oxidation state is less than its group number, and whose magnetic moment in its highest oxidation state is twice its magnetic moment in the atomic state.
Which of the following choices is correct?

1. A The radius of (A) is greater than that of the element after it in the same series.
2. B Element (A) has five stable isotopes.
3. C The melting point of (A) is higher than the melting point of the metal of electricity pylons.
4. D The density of element (A) is less than the density of the element that resists weather conditions.

How many elements ending with the electron configuration (4s , 3d) can form diamagnetic compounds in their highest oxidation states?

1. A 3
2. B 4
3. C 5
4. D 6

Which compound has a cation with the same magnetic moment as the cation of the compound that stops ultraviolet rays from reaching the skin?

1. A Cr₂O₃
2. B MnO₂
3. C V₂O₅
4. D CuO

A transition element of the first transition series reacts very vigorously with water.
Which of the following does not describe this element?

1. A Diamagnetic in the oxidation state (+3).
2. B It has the highest boiling point compared with the elements of the first transition series.
3. C Its electron configuration is ns² , (n−1)dⁿ⁻³
4. D It has many oxidation states.

The opposite graph shows the ionization potentials of a main transition element of the first series.
Each of the following describes this element, except ..........

1. A It is used in making magnets.
2. B It has several radioactive isotopes.
3. C It lies in group 9
4. D It has paramagnetic compounds and diamagnetic compounds

The oxides of transition metals have many economic uses.
Which of the following describes an oxide of one of the metals?

1. A One use of the oxide : used in cosmetics , oxidation number of the metal in this oxide : +5
2. B One use of the oxide : used in making the dry cell , oxidation number of the metal in this oxide : +3
3. C One use of the oxide : a catalyst in the decomposition of H₂O₂ , oxidation number of the metal in this oxide : +4
4. D One use of the oxide : used in the rubber industry , oxidation number of the metal in this oxide : +4

Each of the following describes transition metals or their compounds used as catalysts in some industries, except ..........

1. A V₂O₅ in making sulphuric acid.
2. B Fe in making ammonia.
3. C MnO₂ in making the dry cell.
4. D Ni in the hydrogenation of oils.

Among the properties of element (X) :
• its atomic mass is greater than that of the element before it.
• it gives compounds in which its oxidation number is +2 or +3
• it is used to lower the activation energy of some chemical reactions.
The group number of element (X) is ..........

1. A 7
2. B 10
3. C 6
4. D 8

The electron configuration of the vanadium ion in the catalyst used in the contact process is the same as its electron configuration in the compound ..........

1. A VO₂
2. B VN
3. C VI₃
4. D NH₄VO₃

The opposite graph shows the ionization potentials of one of the elements of the first transition series.
Which of the following describes this element?

1. A Its use as a catalyst in making sulphuric acid.
2. B Its electron configuration is irregular.
3. C It can be magnetized.
4. D Its radius is equal to the radius of iron.

The catalysed reaction : 2SO₂ + O₂ ⟶(cat , Δ) 2SO₃ is one of the steps in preparing a well-known compound.
What is the name of this method, and what is the electron configuration of the atom of the metal used in the catalyst in this process?

1. A Contact / [Ar] , 3d⁰ , 4s⁰
2. B Fischer–Tropsch / [Ar] , 3d⁵ , 4s¹
3. C Fischer–Tropsch / [Ar] , 3d³ , 4s²
4. D Contact / [Ar] , 3d³ , 4s²

Each of the following describes properties of most elements of the first transition series and their reasons, except ..........

1. A Property : paramagnetic substances , reason : the presence of unpaired electrons in the 3d sublevel
2. B Property : their density is high , reason : their atomic sizes are close and their atomic masses are large
3. C Property : ideal catalysts , reason : the ease of losing the two 4s electrons
4. D Property : their melting point is high , reason : the strength of their metallic bonds

The opposite table shows some properties of one of the elements :
• Its melting point : 3422°C
• Its oxidation states : many.
• Density of the element : 19.52 g/cm³
• Its electrical conductivity in the solid state : good.
What other property is this element expected to have?

1. A It has catalytic activity.
2. B The bonding forces between its atoms are weak.
3. C All its ions are diamagnetic.
4. D It lies in the fourth period and group 12

A transition element in the first series has a number of electrons in the (M) level twice its traditional group number in the periodic table.
Each of the following describes this element, except ..........

1. A It lowers the activation energy of the hydrogenation of oils.
2. B It is used to make an alloy that resists corrosion while heated to redness.
3. C It has five stable isotopes.
4. D Its boiling point is higher than the boiling point of iron.

The metal (M) lies in the first transition series :
• its atomic mass is less than the atomic mass of cobalt.
• its melting point is higher than the melting point of nickel.
• its most stable compound with fluorine has the chemical formula : MF₅
Its oxide is used as a catalyst in making ..........

1. A ammonia by the Haber–Bosch process.
2. B hydrogenated oils.
3. C the dry cell.
4. D superconducting magnets.

The opposite graph shows the ionization potentials of a metallic element of the first transition series.
What is a characteristic of this element?

1. A It has only one oxidation state.
2. B Its 3d sublevel contains 3 unpaired electrons.
3. C It is used as an oxidizing agent in the Fischer–Tropsch process.
4. D It is used as a catalyst in making ammonia.

Two elements (A , B) of the first transition series contain the largest number of unpaired electrons, and element (B) gives more oxidation states than element (A).
Which of the following is correct?

1. A Element (B) comes before element (A).
2. B The compound K₂A₂O₇ is an oxidizing substance , BO₂ is a catalyst in the decomposition of H₂O₂
3. C Element (A) lies in group (VIIB) and element (B) lies in group (VIII).
4. D Element (A) resists weather conditions and element (B) is used in its pure state.

Three main transition elements (A , B , C) of the first series :
• (A) has the highest oxidation state in the first transition series.
• (B) has an oxidation state that exceeds its group number.
• (C) one of its compounds is used as a catalyst in preparing H₂SO₄ by the contact process.
What is the correct order of the elements (A , B , C) according to boiling point?

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

The opposite figure shows the activation energy of a reaction before and after using a catalyst.
The activation energy of the catalysed reaction is ..........

1. A 50 kJ
2. B 100 kJ
3. C 130 kJ
4. D 180 kJ

The opposite figure shows the energy diagram of a chemical reaction,
Its activation energy is represented by the value ..........

1. A 2
2. B 3 + 2
3. C 3
4. D 1 − 4

From the opposite energy diagram :
Which of the following is correct?

1. A (1) : energy of the reactants , (3) : activation energy.
2. B (1) : energy of the products , (2) : ΔH°
3. C (1) : energy of the reactants , (3) : ΔH°
4. D (2) : activation energy , (4) : energy of the reactants.

Which of the following graphs shows an exothermic reaction whose activation energy is Eₐ ?

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

The following reaction : 2SO₂(g) + O₂(g) ⟶(V₂O₅ , 450°C) 2SO₃(g) , ΔH = −196 kJ/mol
is shown by the opposite energy diagram, in which the activation energy of the uncatalysed reaction is shown by the letter ..........

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

The compound ammonium sulphate is produced by the reaction of ammonia and sulphuric acid.
Which of the following is correct?

1. A Compound : ammonia , method of preparation : contact , catalyst : iron
2. B Compound : ammonia , method of preparation : Haber – Bosch , catalyst : vanadium pentoxide
3. C Compound : sulphuric acid , method of preparation : contact , catalyst : vanadium pentoxide
4. D Compound : sulphuric acid , method of preparation : Haber – Bosch , catalyst : iron

Which of the following represents the properties of the metal most suitable for making car bodies?

1. A Density : high , strength and toughness : high , corrosion resistance : low
2. B Density : high , strength and toughness : low , corrosion resistance : low
3. C Density : low , strength and toughness : high , corrosion resistance : high
4. D Density : low , strength and toughness : low , corrosion resistance : high

In which of the following compounds does vanadium have the highest oxidation state?

1. A VCl₃
2. B VOSO₄
3. C Na₃VO₄
4. D VSO₄

A transition element (M) lies in the fourth period of the periodic table, and its atom contains three orbitals paired with electrons in the 3d sublevel; the electron configuration of the ion M⁴⁺ is the same as the electron configuration of the ion ..........

1. A Cr³⁺
2. B Mn²⁺
3. C Fe²⁺
4. D Co⁴⁺

Which of the following describes the properties of most transition elements?

1. A Melting point : high , their ions : diamagnetic , most of them used as catalysts : yes
2. B Melting point : high , their ions : paramagnetic , most of them used as catalysts : yes
3. C Melting point : low , their ions : diamagnetic , most of them used as catalysts : no
4. D Melting point : low , their ions : paramagnetic , most of them used as catalysts : no

The following figure shows a part of the periodic table :
(1) Give the numbers of the two elements that can be magnetized.
(2) Give two other similarities in physical properties between these two elements.

Two ions of metals of the first transition series have the electron configuration [Ar] , 3d⁴ :
(1) Give the symbols of these two ions.
(2) Compare the effective nuclear charge of these two metals, and explain.

The transition metal (M) is added to steel to make the alloy used in making car springs. Compare :
(1) the metal (M) and cobalt «in terms of : atomic mass».
(2) the metal (M) and nickel «in terms of : melting point».

Three metals (X) , (Y) , (Z) of the elements of the first transition series :
• Metal (X) : its density is greater than that of the other elements of the series.
• Metal (Y) : its stable oxidation number equals +5
• Metal (Z) : its melting point is higher than the melting points of the other elements of the series.
(1) Arrange these metals according to their boiling points.
(2) Which of the two metals (X) , (Y) has a relatively larger atomic radius?

From the following table, identify the non-transition element, supporting your choice with two reasons :
Element (G) : melting point 1083°C , density 8.92 g/cm³ , reaction with water : does not react , formulas of its chlorides : GCl , GCl₂
Element (J) : melting point 181°C , density 0.53 g/cm³ , reaction with water : very fast , formulas of its chlorides : JCl
Element (L) : melting point 1535°C , density 7.86 g/cm³ , reaction with water : very slow , formulas of its chlorides : LCl₂ , LCl₃

The metal (M) dissolves slowly in dilute sulphuric acid forming a solution of a paramagnetic compound, with gas bubbles given off.
Is the metal (M) scandium or iron? Support your choice with a scientific explanation.

Chromium metal dissolves quickly in dilute sulphuric acid forming a chromium (III) solution.
Write the balanced symbolic equation for this reaction.

The opposite figure shows the energy diagram of a chemical reaction,
What does each of the following represent :
(1) the difference between the two energy values (2) , (1).
(2) the sum of the two energy values (1) , (3).

Hydrogen peroxide H₂O₂ takes part in the following two reactions :
• Reaction (1) : when it is added to a KMnO₄ solution acidified with sulphuric acid, the colour of the permanganate disappears.
• Reaction (2) : when it is added to a FeSO₄ solution, the number of unpaired electrons of the cation of the salt increases.
What role does H₂O₂ play in the two previous reactions? Explain.

A transition metal (M) whose ion M³⁺ has the electron configuration [Ar] , 3d⁵ :
(1) Can the metal (M) be magnetized?
(2) Is the radius of the metal (M) equal to that of the metal after it in the period or not?

The two metals (A) , (B) are elements of the first transition series and have the same atomic radius :
• Metal (A) : has the oxidation state +4 and the cation A⁴⁺ has 5 unpaired electrons.
• Metal (B) : has the oxidation state +2 and the cation B²⁺ has 4 unpaired electrons.
(1) State one use the two metals have in common.
(2) Which has the higher density, metal (A) or metal (B)?

From the transition metals (vanadium , chromium , manganese , titanium) :
(1) Arrange the doubly charged ions of these metals in increasing order of their magnetic moment.
(2) Arrange these elements in increasing order of effective nuclear charge.

Two successive elements (X) , (Y) of the first transition series; element (X) has the highest oxidation state in the series.
Which of the following is correct?
(Sample exam 2026)

1. A Element (Y) is diamagnetic and its atom has 6 unpaired electrons.
2. B Element (X) is diamagnetic and its atom has 6 unpaired electrons.
3. C The ion Y²⁺ is paramagnetic and has 4 unpaired electrons.
4. D The ion X³⁺ is paramagnetic and has 5 unpaired electrons.

Two successive transition elements (X) , (Y) of the first transition series have the same number of electrons in the 3d sublevel
Which of the following is correct?
(Sample exam 2026)

1. A The effective nuclear charge of element (X) is greater than the effective nuclear charge of element (Y).
2. B The radius of element (X) is smaller than the radius of element (Y).
3. C The radius of element (X) equals the radius of element (Y).
4. D The repulsion between the 3d electrons of element (X) is less than the repulsion between the 3d electrons of element (Y).

Which of the following represents the correct order of the ions of some elements according to the strength of their attraction to a magnet?
(Sample exam 2026)

1. A Fe²⁺ > Ti⁴⁺ > Mn²⁺
2. B Mn²⁺ > Fe²⁺ > Ti⁴⁺
3. C Mn²⁺ > Ti⁴⁺ > Fe²⁺
4. D Ti⁴⁺ > Mn²⁺ > Fe²⁺

The following graphs show the values of the ionization potentials of two elements (X) , (Y) :
Which of the following shows the type of the two elements (X) , (Y) and the use of one alloy of each of them?
(Sample exam 2026)

1. A (X) transition : used in aircraft bodies
2. B (X) non-transition : used in MiG aircraft
3. C (Y) transition : used in railway rails
4. D (Y) non-transition : used in soft-drink cans

A transition element (X) of the first transition series is similar in its properties to the element before it and the element after it in the same group,
Which of the following changes happens easily for its ions?
(Sample exam 2026)

1. A X³⁺ ⟶ X²⁺
2. B X⁴⁺ ⟶ X³⁺
3. C X³⁺ ⟶ X⁴⁺
4. D X²⁺ ⟶ X³⁺

Two transition elements (X) , (Y) of the first transition series.
(X) : one of its oxides is used as a catalyst in making superconducting magnets.
(Y) : its atom contains twice the number of unpaired electrons found in element (X).
Which of the following is correct?
(Sample exam 2026)

1. A The atomic radius of element (Y) is less than that of the element after it in the series.
2. B The effective nuclear charge of element (Y) is less than that of element (X).
3. C The highest oxidation state of element (Y) is higher than that of element (X).
4. D The density of element (Y) is less than the density of the element before it in the series.

Two non-successive transition elements (X) , (Y) of the first transition series.
Element (X) : one of its compounds is used as a catalyst in the contact process.
Element (Y) : contains the same number of unpaired electrons as element (X).
Which of the following is correct?
(Sample exam 2026)

1. A The radius of element (X) is greater than the radius of the element directly before it in the series.
2. B The effective nuclear charge of element (Y) is less than that of element (X).
3. C The density of element (Y) is less than the density of element (X).
4. D The atomic mass of element (Y) is greater than the atomic mass of the element directly after it in the series.

Three successive elements (A) , (B) , (C) of the first transition series; element (A) has an electron configuration that is irregular compared with the other elements of the series.
Which of the following shows the correct order of the magnetic moment of the ions of these elements?
(Sample exam 2026)

1. A A³⁺ > B³⁺ > C³⁺
2. B B³⁺ > C³⁺ > A³⁺
3. C B³⁺ > A³⁺ > C³⁺
4. D C³⁺ > B³⁺ > A³⁺

Two successive transition elements (X) , (Y) of the first transition series contain the same number of electrons in the (3d) sublevel, and element (X) resists weather conditions.
Which of the following describes the properties of each of the two elements (X) , (Y)?
(Sample exam 2026)

1. A The density of element (Y) is less than the density of element (X).
2. B The atomic mass of element (X) is greater than the atomic mass of element (Y).
3. C The radius of element (X) is greater than the radius of element (Y).
4. D The effective nuclear charge of element (Y) is greater than that of element (X).

The elements (X) , (Y) , (Z) , (W) are transition elements of the first transition series.
(X) : after it, the pairing of electrons in the (3d) sublevel begins
(Y) : the first element in the series that does not lose all its (4s) , (3d) electrons
(Z) : its (d) sublevel is complete with electrons.
(W) : the highest magnetic moment in the series.
Which of the following changes produces a compound lower in energy?
(Sample exam 2026)

1. A WO₃ ⟶ WO
2. B ZO ⟶ Z₂O₃
3. C Y₂O₃ ⟶ YO
4. D X₂O₃ ⟶ XO

(A) , (B) , (C) are three elements of the first transition series :
The number of unpaired electrons in element (A) decreases when it changes from the atomic state to +2
The number of unpaired electrons in element (B) increases when it changes from +2 to +3
The number of unpaired electrons in element (C) decreases when it changes from +2 to +3 , and its radius equals that of (A)
Which of the following shows the correct trend of these elements according to their density?
(Sample exam 2026)

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

(A) , (B) , (C) , (D) are four successive transition elements of the first transition series, and the electron configuration of the ion B³⁺ ends with 3d³
Which of the following is correct?
(Sample exam 2026)

1. A The magnetic moment of element (A) increases by losing two electrons.
2. B The magnetic moment of element (B) increases by losing two electrons.
3. C The magnetic moment of element (C) decreases by losing the first electron from the (d) level.
4. D The magnetic moment of element (D) decreases by losing the first electron from the (d) level.

An element (X) of the first transition series whose ion X²⁺ contains (11) orbitals filled with electrons and (3) half-filled orbitals.
Which of the following does not describe element (X)?
(Sample exam 2026)

1. A Its atomic mass is less than that of the element after it.
2. B Its density is less than that of the element after it.
3. C All its compounds are paramagnetic.
4. D Its effective nuclear charge is greater than that of the element before it.

(X) , (Y) , (Z) are three transition elements at the end of the first transition series, and their order according to atomic mass is (Y < Z < X)
Which of the following shows the correct order of the ions of these elements according to magnetic moment?
(Sample exam 2026)

1. A Z²⁺ > Y²⁺ > X²⁺
2. B X²⁺ > Y²⁺ > Z²⁺
3. C Z²⁺ > X²⁺ > Y²⁺
4. D X²⁺ > Z²⁺ > Y²⁺

A transition element (A) whose ion (A²⁺) has a magnetic moment less than the magnetic moment of its atom.
Which of the following choices is correct for this element?
(1st session 2025)

1. A It is one of the coinage metals.
2. B It has the highest magnetic moment in its series.
3. C It has an oxidation state higher than its group number.
4. D All its compounds are paramagnetic.

The opposite part of the periodic table contains four elements A , B , C , D :
Which of the following choices is correct?
(1st session 2025)

1. A The effective nuclear charge of element (C) is less than the effective nuclear charge of element (B).
2. B The atomic mass of element (D) is less than the atomic mass of element (C).
3. C The density of element (A) is higher than the density of element (B).
4. D The first ionization potential of element (B) is less than the first ionization potential of element (A).

If you know that the third ionization potential of iron equals 2965 kJ/mol
then the third ionization potential of manganese is ..........
(Sample exam 2025)

1. A 2389 kJ/mol
2. B 2500 kJ/mol
3. C 3250 kJ/mol
4. D 2830 kJ/mol

(A) , (B) , (C) are elements of the first transition series, where :
• (A) : the densest element in the series.
• (B) : the element with the largest radius in the series.
• (C) : a non-transition element.
Which of the following choices is correct?
(2nd session 2024)

1. A (B) : does not react with dilute acids.
2. B (A) : one of its alloys is used in heating coils.
3. C (B) : reacts vigorously with water.
4. D (C) : has more than one oxidation state.

The opposite table shows the electron configuration of the cations of the elements (X) , (Y) , (Z) in their compounds :
X₂O₃ : [₁₈Ar] , 3d³ , YO₂ : [₁₈Ar] , 3d³ , Z₂O₃ : [₁₈Ar] , 3d¹
then the correct order of these elements according to the effective charge of their nuclei is ..........
(2nd session 2023)

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

The drawing in front of you shows the trend in the radius of the transition elements in the fourth period
The element that is irregular in atomic mass is ..........
(2nd session 2022)

1. A C
2. B H
3. C E
4. D D

The drawing in front of you shows the trend in the radius of the transition elements in the fourth period
The element one of whose oxides is used in making pigments is ..........
(1st session 2022)

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

Which of the following choices is correct for the following transition elements?
₂₈Ni , ₂₄Cr , ₂₂Ti , ₂₁Sc
(1st session 2024)

1. A Cr has the highest melting point and the lowest density of them.
2. B Sc has the highest atomic mass and boiling point of them.
3. C Ti has the lowest density and boiling point of them.
4. D Ni has the highest density and atomic mass of them.

The following statements describe properties of some elements of the first transition series.
Which of them represents the densest element?
(Trial exam / March 2023)

1. A Its atomic mass is less than the atomic mass of the element before it.
2. B It has the largest magnetic moment in the atomic state.
3. C Its 3+ ion is difficult to reduce to a 2+ ion
4. D The largest atomic size of the elements of the first transition series.

From the opposite graph :
Which of the following choices is correct?
(1st session 2023)

1. A Element (Z) is less dense than element (W).
2. B Element (Y) is less dense than element (Z).
3. C Element (W) has a higher ionization potential than element (X).
4. D Element (X) has a higher ionization potential than element (Y).

The elements (X) , (Y) , (Z) are successive transition elements at the end of the first transition series; the largest in atomic number is element (X), and they have the following compounds XA₂ , YA₂ , ZA₂
then the correct order according to the magnetic moment of their ions is ..........
(1st session 2021)

1. A Z²⁺ > Y²⁺ > X²⁺
2. B X²⁺ > Y²⁺ > Z²⁺
3. C Z²⁺ > X²⁺ > Y²⁺
4. D X²⁺ > Z²⁺ > Y²⁺

A main transition element of the first transition series has the largest magnetic moment in its oxidation state (2+).
Then the electron configuration of this element in the oxidation state (3+) is ..........
(2nd session 2022)

1. A [₁₈Ar] , 4s⁰ , 3d⁵
2. B [₁₈Ar] , 4s² , 3d⁵
3. C [₁₈Ar] , 4s⁰ , 3d³
4. D [₁₈Ar] , 4s⁰ , 3d⁴

An element (X) whose electron configuration ends with the sublevel 3d⁷ , so the compound XCl₃ has ..........
(2nd session 2021)

1. A zero unpaired electrons.
2. B 2 unpaired electrons.
3. C 4 unpaired electrons.
4. D 3 unpaired electrons.

The elements (X) , (Y) , (Z) , (W) are of the first transition series :
(1) The cation of (XCl₂) has the lowest magnetic moment and element (X) has the highest atomic mass.
(2) The cation of (YCl₃) is paramagnetic and its highest oxidation state is +5
(3) The cation of (ZCl₂) is diamagnetic and Z is used in galvanizing metals.
(4) The cation of (WCl₃) has the highest magnetic moment and element (W) is of moderate chemical activity.
Deduce the names of each of the elements (X) , (Y) , (Z) , (W).
(2nd session 2024)

The opposite table shows the electron configuration of the cations of some elements; study it well, then answer :
A²⁺ : [₁₈Ar] , 3d⁷ , B²⁺ : [₁₈Ar] , 3d¹⁰ , C³⁺ : [₁₈Ar] , D⁴⁺ : [₁₈Ar] , 3d³
(1) From the cations of the opposite elements, deduce :
(a) the element that has the largest magnetic moment.
(b) the element that has the smallest magnetic moment.
(2) Which cation has an oxide used to lower the activation energy of the decomposition of H₂O₂(l)?
(2nd session 2023)

From the following compounds : VCl₅ , CuSO₄ , Fe₂(SO₄)₃ , CrCl₃
Which of the previous compounds is a compound :
(1) diamagnetic, whose cation is in the highest oxidation state.
(2) one of the compounds of its cation has a medical use, and it has the smallest magnetic moment.
(3) whose cation has the largest magnetic moment.
(4) paramagnetic, whose cation contains 3 unpaired electrons.
(1st session 2024)

(X) , (Y) are two elements of the first transition series :
• The oxide of element (X) is a catalyst in preparing oxygen.
• Element (Y) forms an alloy with element (X).
Deduce the cation that has the larger magnetic moment in the following oxides X₂O₃ , Y₂O₃ , and explain.
(Trial exam / March 2023)

The opposite graph shows the relation between the magnetic moment of some cations of the first transition series in order; deduce :
(1) the magnetic properties of the cations D⁶⁺ , B⁶⁺
(2) the cations whose elements are used to lower the activation energy.
(1st session 2023)