Periodic Table and Periodicity MCQs 2026

76 questions with detailed answers · 27 from past papers · 8 quiz batches available

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Page 1 of 1 Questions 1–10 of 76

Q1 easy

The modern periodic table arranges elements in order of increasing
1. A Atomic mass
2. B Atomic number
3. C Number of neutrons
4. D Number of isotopes
💡 Explanation:
Moseley's work established atomic number as the basis of the modern periodic table.
Q2 Past Paper · PPSC/FPSC/NTS easy

Mendeleev arranged the elements in the periodic table mainly in order of increasing
1. A Atomic number
2. B Number of valence electrons
3. C Atomic mass
4. D Electronegativity
💡 Explanation:
Mendeleev's original table was ordered by increasing atomic mass.
Q3 Past Paper · PPSC/FPSC/NTS easy

The horizontal rows of the periodic table are called
1. A Periods
2. B Groups
3. C Blocks
4. D Series
💡 Explanation:
Horizontal rows are called periods, numbered 1 through 7.
Q4 easy

The vertical columns of the periodic table are called
1. A Groups
2. B Periods
3. C Blocks
4. D Rows
💡 Explanation:
Vertical columns are called groups or families, numbered 1 through 18.
Q5 Past Paper · PPSC/FPSC/NTS easy

The number of periods in the modern periodic table is
1. A 6
2. B 5
3. C 8
4. D 7
💡 Explanation:
The periodic table has seven periods.
Q6 easy

Elements in the same group of the periodic table have the same number of
1. A Neutrons
2. B Protons
3. C Energy levels
4. D Valence electrons
💡 Explanation:
Elements in a group share the same number of valence electrons, giving similar chemical properties.
Q7 Past Paper · PPSC/FPSC/NTS easy

Atomic radius generally ___ across a period from left to right
1. A Decreases
2. B Increases
3. C Remains constant
4. D First increases then decreases
💡 Explanation:
Increasing nuclear charge pulls electrons closer, shrinking atomic radius across a period.
Q8 easy

Atomic radius generally ___ down a group
1. A Decreases
2. B Remains constant
3. C Fluctuates
4. D Increases
💡 Explanation:
Additional electron shells are added down a group, increasing atomic radius.
Q9 Past Paper · PPSC/FPSC/NTS easy

Ionization energy generally ___ across a period from left to right
1. A Decreases
2. B Increases
3. C Remains unchanged
4. D Becomes negative
💡 Explanation:
Increasing nuclear charge holds electrons more tightly, raising ionization energy across a period.
Q10 easy

Ionization energy generally ___ down a group
1. A Decreases
2. B Increases
3. C Remains constant
4. D Doubles
💡 Explanation:
Outer electrons are farther from the nucleus and more shielded, lowering ionization energy down a group.
Q11 medium

Electronegativity is highest for which of the following elements
1. A Cesium
2. B Sodium
3. C Oxygen
4. D Fluorine
💡 Explanation:
Fluorine has the highest electronegativity of all elements on the Pauling scale.
Q12 Past Paper · PPSC/FPSC/NTS medium

Elements of Group 1 (excluding hydrogen) are known as
1. A Alkali metals
2. B Alkaline earth metals
3. C Halogens
4. D Noble gases
💡 Explanation:
Group 1 metals like sodium and potassium are called alkali metals.
Q13 medium

Elements of Group 2 are known as
1. A Alkaline earth metals
2. B Alkali metals
3. C Chalcogens
4. D Halogens
💡 Explanation:
Group 2 elements such as calcium and magnesium are alkaline earth metals.
Q14 Past Paper · PPSC/FPSC/NTS medium

Elements of Group 17 are known as
1. A Noble gases
2. B Halogens
3. C Chalcogens
4. D Pnictogens
💡 Explanation:
Group 17 elements like chlorine and fluorine are called halogens.
Q15 medium

Elements of Group 18 are known as
1. A Halogens
2. B Alkali metals
3. C Transition metals
4. D Noble gases
💡 Explanation:
Group 18 elements are chemically inert noble gases.
Q16 medium

Elements between Group 3 and Group 12 are called
1. A Lanthanides
2. B Actinides
3. C Transition elements
4. D Metalloids
💡 Explanation:
The d-block elements spanning groups 3-12 are known as transition elements.
Q17 Past Paper · PPSC/FPSC/NTS medium

Which of the following is a metalloid
1. A Sodium
2. B Chlorine
3. C Silicon
4. D Magnesium
💡 Explanation:
Silicon exhibits properties intermediate between metals and non-metals, classifying it as a metalloid.
Q18 medium

The most electronegative element in the periodic table is
1. A Chlorine
2. B Fluorine
3. C Oxygen
4. D Nitrogen
💡 Explanation:
Fluorine tops the electronegativity scale at 4.0 on the Pauling scale.
Q19 medium

The element with the smallest atomic radius in period 2 is
1. A Lithium
2. B Boron
3. C Fluorine
4. D Beryllium
💡 Explanation:
Atomic radius decreases across period 2, making fluorine the smallest before neon.
Q20 Past Paper · PPSC/FPSC/NTS medium

Metallic character generally ___ down a group
1. A Decreases
2. B Increases
3. C Remains the same
4. D Disappears
💡 Explanation:
Increased atomic size and reduced ionization energy down a group enhance metallic character.
Q21 medium

Metallic character generally ___ across a period from left to right
1. A Increases
2. B Decreases
3. C Stays constant
4. D Doubles
💡 Explanation:
Increasing ionization energy across a period reduces metallic character.
Q22 medium

Which of the following elements belongs to the lanthanide series
1. A Uranium
2. B Thorium
3. C Cerium
4. D Actinium
💡 Explanation:
Cerium is a member of the lanthanide series (atomic numbers 58-71).
Q23 Past Paper · PPSC/FPSC/NTS medium

The elements from atomic number 90 to 103 are called
1. A Lanthanides
2. B Actinides
3. C Transition metals
4. D Noble gases
💡 Explanation:
Actinides span atomic numbers 89/90 to 103, mostly radioactive elements.
Q24 medium

The number of elements in the lanthanide series is
1. A 15
2. B 14
3. C 10
4. D 18
💡 Explanation:
The lanthanide series conventionally comprises 14 elements after lanthanum.
Q25 medium

Which of the following has the largest atomic radius
1. A Fluorine
2. B Cesium
3. C Chlorine
4. D Neon
💡 Explanation:
Cesium, at the bottom-left of the periodic table, has one of the largest atomic radii.
Q26 Past Paper · PPSC/FPSC/NTS medium

The first ionization energy is highest for which noble gas
1. A Xenon
2. B Argon
3. C Krypton
4. D Helium
💡 Explanation:
Helium has the smallest atomic size and highest ionization energy among noble gases.
Q27 medium

Electron affinity is generally highest (most negative) for
1. A Alkali metals
2. B Noble gases
3. C Halogens
4. D Alkaline earth metals
💡 Explanation:
Halogens readily accept an electron to complete their octet, releasing significant energy.
Q28 medium

The s-block of the periodic table consists of groups
1. A 1 and 2
2. B 13 and 14
3. C 17 and 18
4. D 3 to 12
💡 Explanation:
Group 1 and Group 2 elements fill their outermost s-subshell, forming the s-block.
Q29 Past Paper · PPSC/FPSC/NTS medium

The d-block elements are also known as
1. A Representative elements
2. B Inner transition elements
3. C Transition elements
4. D Noble gases
💡 Explanation:
d-block elements (groups 3-12) are commonly called transition elements.
Q30 medium

The f-block elements are also known as
1. A Transition elements
2. B Representative elements
3. C Inner transition elements
4. D Metalloids
💡 Explanation:
Lanthanides and actinides, filling f-subshells, are called inner transition elements.
Q31 medium

Which law states that properties of elements are a periodic function of their atomic number
1. A Dalton's law
2. B Law of octaves
3. C Avogadro's law
4. D Modern periodic law
💡 Explanation:
The modern periodic law replaced atomic mass with atomic number as the ordering principle.
Q32 Past Paper · PPSC/FPSC/NTS medium

Newlands' law of octaves stated that every eighth element resembled the
1. A Second element
2. B First element
3. C Sixth element
4. D Last element
💡 Explanation:
Newlands noticed a repeating pattern where every eighth element had similar properties to the first.
Q33 medium

The element predicted by Mendeleev as 'eka-silicon' was later identified as
1. A Gallium
2. B Scandium
3. C Technetium
4. D Germanium
💡 Explanation:
Germanium was discovered later and matched Mendeleev's predicted properties for eka-silicon.
Q34 medium

Which of the following is an exception to the general trend of increasing atomic number order with atomic mass in Mendeleev's table
1. A Argon and Potassium
2. B Sodium and Magnesium
3. C Carbon and Nitrogen
4. D Helium and Lithium
💡 Explanation:
Argon has a higher atomic mass than potassium despite having a lower atomic number, an anomaly in mass-based ordering.
Q35 Past Paper · PPSC/FPSC/NTS medium

Group 14 elements are also called
1. A Carbon family
2. B Nitrogen family
3. C Oxygen family
4. D Boron family
💡 Explanation:
Group 14, headed by carbon, is known as the carbon family.
Q36 medium

Group 15 elements are also called
1. A Carbon family
2. B Oxygen family
3. C Boron family
4. D Nitrogen family (Pnictogens)
💡 Explanation:
Group 15, headed by nitrogen, is called the nitrogen family or pnictogens.
Q37 medium

Group 16 elements are also called
1. A Halogens
2. B Nitrogen family
3. C Boron family
4. D Chalcogens
💡 Explanation:
Group 16 elements, including oxygen and sulfur, are known as chalcogens.
Q38 Past Paper · PPSC/FPSC/NTS medium

Which period contains only 2 elements
1. A Period 2
2. B Period 3
3. C Period 1
4. D Period 4
💡 Explanation:
Period 1 contains only hydrogen and helium.
Q39 medium

The number of elements in period 3 of the periodic table is
1. A 8
2. B 18
3. C 2
4. D 32
💡 Explanation:
Period 3 runs from sodium to argon, containing 8 elements.
Q40 medium

The number of elements in period 4 of the periodic table is
1. A 18
2. B 8
3. C 32
4. D 2
💡 Explanation:
Period 4 includes the first row of transition metals, totaling 18 elements.
Q41 Past Paper · PPSC/FPSC/NTS hard

Which of the following elements has the highest electronegativity on the Pauling scale
1. A Chlorine (3.0)
2. B Nitrogen (3.0)
3. C Fluorine (4.0)
4. D Oxygen (3.5)
💡 Explanation:
Fluorine's Pauling electronegativity value of 4.0 is the highest of any element.
Q42 hard

The diagonal relationship in the periodic table is best shown between
1. A Sodium and Magnesium
2. B Potassium and Calcium
3. C Lithium and Magnesium
4. D Boron and Silicon
💡 Explanation:
Lithium and magnesium show similar chemical properties due to comparable charge density, a classic diagonal relationship.
Q43 hard

Which of the following statements about ionic radius is correct
1. A Cations are larger than their parent atoms
2. B Anions are smaller than their parent atoms
3. C Isoelectronic ions all have equal radii
4. D Cations are smaller than their parent atoms
💡 Explanation:
Losing electrons reduces electron-electron repulsion, shrinking the resulting cation.
Q44 Past Paper · PPSC/FPSC/NTS hard

Isoelectronic species have the same number of
1. A Protons
2. B Electrons
3. C Neutrons
4. D Valence shells only
💡 Explanation:
Isoelectronic species share an identical electron count, regardless of protons.
Q45 hard

Which of the following ions is isoelectronic with neon
1. A Na+
2. B K+
3. C Ca2+
4. D Li+
💡 Explanation:
Na+ loses one electron from its 11, leaving 10 electrons, the same as neon.
Q46 hard

The periodic table is divided into blocks based on the
1. A Atomic mass
2. B Type of subshell being filled by the last electron
3. C Number of isotopes
4. D Boiling point
💡 Explanation:
s, p, d, and f blocks are named for the subshell receiving the atom's last electron.
Q47 Past Paper · PPSC/FPSC/NTS hard

Which of the following elements is a liquid at room temperature
1. A Sodium
2. B Iodine
3. C Bromine
4. D Chlorine
💡 Explanation:
Bromine is one of only two elements that are liquid at standard room temperature.
Q48 hard

Which gas is used to fill electric bulbs due to its inertness
1. A Oxygen
2. B Hydrogen
3. C Argon
4. D Nitrogen
💡 Explanation:
Argon's chemical inertness prevents the filament from reacting or burning out quickly.
Q49 hard

The lightest element in the periodic table is
1. A Hydrogen
2. B Helium
3. C Lithium
4. D Boron
💡 Explanation:
Hydrogen has the lowest atomic mass of all elements.
Q50 hard

The element with atomic number 1 is
1. A Helium
2. B Lithium
3. C Carbon
4. D Hydrogen
💡 Explanation:
Hydrogen, with one proton, has atomic number 1.
Q51 Past Paper · PPSC/FPSC/NTS medium

Which of the following is a metalloid
1. A Sodium
2. B Chlorine
3. C Silicon
4. D Magnesium
💡 Explanation:
Silicon exhibits properties intermediate between metals and non-metals, classifying it as a metalloid.
Q52 medium

The most electronegative element in the periodic table is
1. A Chlorine
2. B Fluorine
3. C Oxygen
4. D Nitrogen
💡 Explanation:
Fluorine tops the electronegativity scale at 4.0 on the Pauling scale.
Q53 medium

The element with the smallest atomic radius in period 2 is
1. A Lithium
2. B Boron
3. C Fluorine
4. D Beryllium
💡 Explanation:
Atomic radius decreases across period 2, making fluorine the smallest before neon.
Q54 Past Paper · PPSC/FPSC/NTS medium

Metallic character generally ___ down a group
1. A Decreases
2. B Increases
3. C Remains the same
4. D Disappears
💡 Explanation:
Increased atomic size and reduced ionization energy down a group enhance metallic character.
Q55 medium

Metallic character generally ___ across a period from left to right
1. A Increases
2. B Decreases
3. C Stays constant
4. D Doubles
💡 Explanation:
Increasing ionization energy across a period reduces metallic character.
Q56 medium

Which of the following elements belongs to the lanthanide series
1. A Uranium
2. B Thorium
3. C Cerium
4. D Actinium
💡 Explanation:
Cerium is a member of the lanthanide series (atomic numbers 58-71).
Q57 Past Paper · PPSC/FPSC/NTS medium

The elements from atomic number 90 to 103 are called
1. A Lanthanides
2. B Actinides
3. C Transition metals
4. D Noble gases
💡 Explanation:
Actinides span atomic numbers 89/90 to 103, mostly radioactive elements.
Q58 medium

The number of elements in the lanthanide series is
1. A 15
2. B 14
3. C 10
4. D 18
💡 Explanation:
The lanthanide series conventionally comprises 14 elements after lanthanum.
Q59 medium

Which of the following has the largest atomic radius
1. A Fluorine
2. B Cesium
3. C Chlorine
4. D Neon
💡 Explanation:
Cesium, at the bottom-left of the periodic table, has one of the largest atomic radii.
Q60 Past Paper · PPSC/FPSC/NTS medium

The first ionization energy is highest for which noble gas
1. A Xenon
2. B Argon
3. C Krypton
4. D Helium
💡 Explanation:
Helium has the smallest atomic size and highest ionization energy among noble gases.
Q61 medium

Electron affinity is generally highest (most negative) for
1. A Alkali metals
2. B Noble gases
3. C Halogens
4. D Alkaline earth metals
💡 Explanation:
Halogens readily accept an electron to complete their octet, releasing significant energy.
Q62 medium

The s-block of the periodic table consists of groups
1. A 1 and 2
2. B 13 and 14
3. C 17 and 18
4. D 3 to 12
💡 Explanation:
Group 1 and Group 2 elements fill their outermost s-subshell, forming the s-block.
Q63 Past Paper · PPSC/FPSC/NTS medium

The d-block elements are also known as
1. A Representative elements
2. B Inner transition elements
3. C Transition elements
4. D Noble gases
💡 Explanation:
d-block elements (groups 3-12) are commonly called transition elements.
Q64 medium

The f-block elements are also known as
1. A Transition elements
2. B Representative elements
3. C Inner transition elements
4. D Metalloids
💡 Explanation:
Lanthanides and actinides, filling f-subshells, are called inner transition elements.
Q65 medium

Which law states that properties of elements are a periodic function of their atomic number
1. A Dalton's law
2. B Law of octaves
3. C Avogadro's law
4. D Modern periodic law
💡 Explanation:
The modern periodic law replaced atomic mass with atomic number as the ordering principle.
Q66 Past Paper · PPSC/FPSC/NTS medium

Newlands' law of octaves stated that every eighth element resembled the
1. A Second element
2. B First element
3. C Sixth element
4. D Last element
💡 Explanation:
Newlands noticed a repeating pattern where every eighth element had similar properties to the first.
Q67 medium

The element predicted by Mendeleev as 'eka-silicon' was later identified as
1. A Gallium
2. B Scandium
3. C Technetium
4. D Germanium
💡 Explanation:
Germanium was discovered later and matched Mendeleev's predicted properties for eka-silicon.
Q68 medium

Which of the following is an exception to the general trend of increasing atomic number order with atomic mass in Mendeleev's table
1. A Argon and Potassium
2. B Sodium and Magnesium
3. C Carbon and Nitrogen
4. D Helium and Lithium
💡 Explanation:
Argon has a higher atomic mass than potassium despite having a lower atomic number, an anomaly in mass-based ordering.
Q69 Past Paper · PPSC/FPSC/NTS medium

Group 14 elements are also called
1. A Carbon family
2. B Nitrogen family
3. C Oxygen family
4. D Boron family
💡 Explanation:
Group 14, headed by carbon, is known as the carbon family.
Q70 medium

Group 15 elements are also called
1. A Carbon family
2. B Oxygen family
3. C Boron family
4. D Nitrogen family (Pnictogens)
💡 Explanation:
Group 15, headed by nitrogen, is called the nitrogen family or pnictogens.
Q71 medium

Group 16 elements are also called
1. A Halogens
2. B Nitrogen family
3. C Boron family
4. D Chalcogens
💡 Explanation:
Group 16 elements, including oxygen and sulfur, are known as chalcogens.
Q72 Past Paper · PPSC/FPSC/NTS medium

Which period contains only 2 elements
1. A Period 2
2. B Period 3
3. C Period 1
4. D Period 4
💡 Explanation:
Period 1 contains only hydrogen and helium.
Q73 medium

The number of elements in period 3 of the periodic table is
1. A 8
2. B 18
3. C 2
4. D 32
💡 Explanation:
Period 3 runs from sodium to argon, containing 8 elements.
Q74 medium

The number of elements in period 4 of the periodic table is
1. A 18
2. B 8
3. C 32
4. D 2
💡 Explanation:
Period 4 includes the first row of transition metals, totaling 18 elements.
Q75 Past Paper · PPSC/FPSC/NTS hard

Which of the following elements has the highest electronegativity on the Pauling scale
1. A Chlorine (3.0)
2. B Nitrogen (3.0)
3. C Fluorine (4.0)
4. D Oxygen (3.5)
💡 Explanation:
Fluorine's Pauling electronegativity value of 4.0 is the highest of any element.
Q76 hard

The diagonal relationship in the periodic table is best shown between
1. A Sodium and Magnesium
2. B Potassium and Calcium
3. C Lithium and Magnesium
4. D Boron and Silicon
💡 Explanation:
Lithium and magnesium show similar chemical properties due to comparable charge density, a classic diagonal relationship.

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Periodic Table and Periodicity MCQs 2026

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