Periodic Table and Periodicity MCQs 2026

50 questions with detailed answers · 18 from past papers · 5 quiz batches available

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Page 1 of 1Questions 1–10 of 50

Q1easy
The modern periodic table arranges elements in order of increasing
1. AAtomic mass
2. BAtomic number
3. CNumber of neutrons
4. DNumber of isotopes
💡 Explanation:
Moseley's work established atomic number as the basis of the modern periodic table.
Q2Past Paper · PPSC/FPSC/NTSeasy
Mendeleev arranged the elements in the periodic table mainly in order of increasing
1. AAtomic number
2. BNumber of valence electrons
3. CAtomic mass
4. DElectronegativity
💡 Explanation:
Mendeleev's original table was ordered by increasing atomic mass.
Q3Past Paper · PPSC/FPSC/NTSeasy
The horizontal rows of the periodic table are called
1. APeriods
2. BGroups
3. CBlocks
4. DSeries
💡 Explanation:
Horizontal rows are called periods, numbered 1 through 7.
Q4easy
The vertical columns of the periodic table are called
1. AGroups
2. BPeriods
3. CBlocks
4. DRows
💡 Explanation:
Vertical columns are called groups or families, numbered 1 through 18.
Q5Past Paper · PPSC/FPSC/NTSeasy
The number of periods in the modern periodic table is
1. A6
2. B5
3. C8
4. D7
💡 Explanation:
The periodic table has seven periods.
Q6easy
Elements in the same group of the periodic table have the same number of
1. ANeutrons
2. BProtons
3. CEnergy levels
4. DValence electrons
💡 Explanation:
Elements in a group share the same number of valence electrons, giving similar chemical properties.
Q7Past Paper · PPSC/FPSC/NTSeasy
Atomic radius generally ___ across a period from left to right
1. ADecreases
2. BIncreases
3. CRemains constant
4. DFirst increases then decreases
💡 Explanation:
Increasing nuclear charge pulls electrons closer, shrinking atomic radius across a period.
Q8easy
Atomic radius generally ___ down a group
1. ADecreases
2. BRemains constant
3. CFluctuates
4. DIncreases
💡 Explanation:
Additional electron shells are added down a group, increasing atomic radius.
Q9Past Paper · PPSC/FPSC/NTSeasy
Ionization energy generally ___ across a period from left to right
1. ADecreases
2. BIncreases
3. CRemains unchanged
4. DBecomes negative
💡 Explanation:
Increasing nuclear charge holds electrons more tightly, raising ionization energy across a period.
Q10easy
Ionization energy generally ___ down a group
1. ADecreases
2. BIncreases
3. CRemains constant
4. DDoubles
💡 Explanation:
Outer electrons are farther from the nucleus and more shielded, lowering ionization energy down a group.
Q11medium
Electronegativity is highest for which of the following elements
1. ACesium
2. BSodium
3. COxygen
4. DFluorine
💡 Explanation:
Fluorine has the highest electronegativity of all elements on the Pauling scale.
Q12Past Paper · PPSC/FPSC/NTSmedium
Elements of Group 1 (excluding hydrogen) are known as
1. AAlkali metals
2. BAlkaline earth metals
3. CHalogens
4. DNoble gases
💡 Explanation:
Group 1 metals like sodium and potassium are called alkali metals.
Q13medium
Elements of Group 2 are known as
1. AAlkaline earth metals
2. BAlkali metals
3. CChalcogens
4. DHalogens
💡 Explanation:
Group 2 elements such as calcium and magnesium are alkaline earth metals.
Q14Past Paper · PPSC/FPSC/NTSmedium
Elements of Group 17 are known as
1. ANoble gases
2. BHalogens
3. CChalcogens
4. DPnictogens
💡 Explanation:
Group 17 elements like chlorine and fluorine are called halogens.
Q15medium
Elements of Group 18 are known as
1. AHalogens
2. BAlkali metals
3. CTransition metals
4. DNoble gases
💡 Explanation:
Group 18 elements are chemically inert noble gases.
Q16medium
Elements between Group 3 and Group 12 are called
1. ALanthanides
2. BActinides
3. CTransition elements
4. DMetalloids
💡 Explanation:
The d-block elements spanning groups 3-12 are known as transition elements.
Q17Past Paper · PPSC/FPSC/NTSmedium
Which of the following is a metalloid
1. ASodium
2. BChlorine
3. CSilicon
4. DMagnesium
💡 Explanation:
Silicon exhibits properties intermediate between metals and non-metals, classifying it as a metalloid.
Q18medium
The most electronegative element in the periodic table is
1. AChlorine
2. BFluorine
3. COxygen
4. DNitrogen
💡 Explanation:
Fluorine tops the electronegativity scale at 4.0 on the Pauling scale.
Q19medium
The element with the smallest atomic radius in period 2 is
1. ALithium
2. BBoron
3. CFluorine
4. DBeryllium
💡 Explanation:
Atomic radius decreases across period 2, making fluorine the smallest before neon.
Q20Past Paper · PPSC/FPSC/NTSmedium
Metallic character generally ___ down a group
1. ADecreases
2. BIncreases
3. CRemains the same
4. DDisappears
💡 Explanation:
Increased atomic size and reduced ionization energy down a group enhance metallic character.
Q21medium
Metallic character generally ___ across a period from left to right
1. AIncreases
2. BDecreases
3. CStays constant
4. DDoubles
💡 Explanation:
Increasing ionization energy across a period reduces metallic character.
Q22medium
Which of the following elements belongs to the lanthanide series
1. AUranium
2. BThorium
3. CCerium
4. DActinium
💡 Explanation:
Cerium is a member of the lanthanide series (atomic numbers 58-71).
Q23Past Paper · PPSC/FPSC/NTSmedium
The elements from atomic number 90 to 103 are called
1. ALanthanides
2. BActinides
3. CTransition metals
4. DNoble gases
💡 Explanation:
Actinides span atomic numbers 89/90 to 103, mostly radioactive elements.
Q24medium
The number of elements in the lanthanide series is
1. A15
2. B14
3. C10
4. D18
💡 Explanation:
The lanthanide series conventionally comprises 14 elements after lanthanum.
Q25medium
Which of the following has the largest atomic radius
1. AFluorine
2. BCesium
3. CChlorine
4. DNeon
💡 Explanation:
Cesium, at the bottom-left of the periodic table, has one of the largest atomic radii.
Q26Past Paper · PPSC/FPSC/NTSmedium
The first ionization energy is highest for which noble gas
1. AXenon
2. BArgon
3. CKrypton
4. DHelium
💡 Explanation:
Helium has the smallest atomic size and highest ionization energy among noble gases.
Q27medium
Electron affinity is generally highest (most negative) for
1. AAlkali metals
2. BNoble gases
3. CHalogens
4. DAlkaline earth metals
💡 Explanation:
Halogens readily accept an electron to complete their octet, releasing significant energy.
Q28medium
The s-block of the periodic table consists of groups
1. A1 and 2
2. B13 and 14
3. C17 and 18
4. D3 to 12
💡 Explanation:
Group 1 and Group 2 elements fill their outermost s-subshell, forming the s-block.
Q29Past Paper · PPSC/FPSC/NTSmedium
The d-block elements are also known as
1. ARepresentative elements
2. BInner transition elements
3. CTransition elements
4. DNoble gases
💡 Explanation:
d-block elements (groups 3-12) are commonly called transition elements.
Q30medium
The f-block elements are also known as
1. ATransition elements
2. BRepresentative elements
3. CInner transition elements
4. DMetalloids
💡 Explanation:
Lanthanides and actinides, filling f-subshells, are called inner transition elements.
Q31medium
Which law states that properties of elements are a periodic function of their atomic number
1. ADalton's law
2. BLaw of octaves
3. CAvogadro's law
4. DModern periodic law
💡 Explanation:
The modern periodic law replaced atomic mass with atomic number as the ordering principle.
Q32Past Paper · PPSC/FPSC/NTSmedium
Newlands' law of octaves stated that every eighth element resembled the
1. ASecond element
2. BFirst element
3. CSixth element
4. DLast element
💡 Explanation:
Newlands noticed a repeating pattern where every eighth element had similar properties to the first.
Q33medium
The element predicted by Mendeleev as 'eka-silicon' was later identified as
1. AGallium
2. BScandium
3. CTechnetium
4. DGermanium
💡 Explanation:
Germanium was discovered later and matched Mendeleev's predicted properties for eka-silicon.
Q34medium
Which of the following is an exception to the general trend of increasing atomic number order with atomic mass in Mendeleev's table
1. AArgon and Potassium
2. BSodium and Magnesium
3. CCarbon and Nitrogen
4. DHelium and Lithium
💡 Explanation:
Argon has a higher atomic mass than potassium despite having a lower atomic number, an anomaly in mass-based ordering.
Q35Past Paper · PPSC/FPSC/NTSmedium
Group 14 elements are also called
1. ACarbon family
2. BNitrogen family
3. COxygen family
4. DBoron family
💡 Explanation:
Group 14, headed by carbon, is known as the carbon family.
Q36medium
Group 15 elements are also called
1. ACarbon family
2. BOxygen family
3. CBoron family
4. DNitrogen family (Pnictogens)
💡 Explanation:
Group 15, headed by nitrogen, is called the nitrogen family or pnictogens.
Q37medium
Group 16 elements are also called
1. AHalogens
2. BNitrogen family
3. CBoron family
4. DChalcogens
💡 Explanation:
Group 16 elements, including oxygen and sulfur, are known as chalcogens.
Q38Past Paper · PPSC/FPSC/NTSmedium
Which period contains only 2 elements
1. APeriod 2
2. BPeriod 3
3. CPeriod 1
4. DPeriod 4
💡 Explanation:
Period 1 contains only hydrogen and helium.
Q39medium
The number of elements in period 3 of the periodic table is
1. A8
2. B18
3. C2
4. D32
💡 Explanation:
Period 3 runs from sodium to argon, containing 8 elements.
Q40medium
The number of elements in period 4 of the periodic table is
1. A18
2. B8
3. C32
4. D2
💡 Explanation:
Period 4 includes the first row of transition metals, totaling 18 elements.
Q41Past Paper · PPSC/FPSC/NTShard
Which of the following elements has the highest electronegativity on the Pauling scale
1. AChlorine (3.0)
2. BNitrogen (3.0)
3. CFluorine (4.0)
4. DOxygen (3.5)
💡 Explanation:
Fluorine's Pauling electronegativity value of 4.0 is the highest of any element.
Q42hard
The diagonal relationship in the periodic table is best shown between
1. ASodium and Magnesium
2. BPotassium and Calcium
3. CLithium and Magnesium
4. DBoron and Silicon
💡 Explanation:
Lithium and magnesium show similar chemical properties due to comparable charge density, a classic diagonal relationship.
Q43hard
Which of the following statements about ionic radius is correct
1. ACations are larger than their parent atoms
2. BAnions are smaller than their parent atoms
3. CIsoelectronic ions all have equal radii
4. DCations are smaller than their parent atoms
💡 Explanation:
Losing electrons reduces electron-electron repulsion, shrinking the resulting cation.
Q44Past Paper · PPSC/FPSC/NTShard
Isoelectronic species have the same number of
1. AProtons
2. BElectrons
3. CNeutrons
4. DValence shells only
💡 Explanation:
Isoelectronic species share an identical electron count, regardless of protons.
Q45hard
Which of the following ions is isoelectronic with neon
1. ANa+
2. BK+
3. CCa2+
4. DLi+
💡 Explanation:
Na+ loses one electron from its 11, leaving 10 electrons, the same as neon.
Q46hard
The periodic table is divided into blocks based on the
1. AAtomic mass
2. BType of subshell being filled by the last electron
3. CNumber of isotopes
4. DBoiling point
💡 Explanation:
s, p, d, and f blocks are named for the subshell receiving the atom's last electron.
Q47Past Paper · PPSC/FPSC/NTShard
Which of the following elements is a liquid at room temperature
1. ASodium
2. BIodine
3. CBromine
4. DChlorine
💡 Explanation:
Bromine is one of only two elements that are liquid at standard room temperature.
Q48hard
Which gas is used to fill electric bulbs due to its inertness
1. AOxygen
2. BHydrogen
3. CArgon
4. DNitrogen
💡 Explanation:
Argon's chemical inertness prevents the filament from reacting or burning out quickly.
Q49hard
The lightest element in the periodic table is
1. AHydrogen
2. BHelium
3. CLithium
4. DBoron
💡 Explanation:
Hydrogen has the lowest atomic mass of all elements.
Q50hard
The element with atomic number 1 is
1. AHelium
2. BLithium
3. CCarbon
4. DHydrogen
💡 Explanation:
Hydrogen, with one proton, has atomic number 1.

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Periodic Table and Periodicity MCQs 2026

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