JEE Chemistry Classification Of Elements and Periodicity In Properties MCQs Set 26

Download JEE MCQs for JEE Chemistry: Classification Of Elements and Periodicity In Properties

Access targeted multiple-choice questions for Classification Of Elements and Periodicity In Properties designed to align with the latest JEE academic syllabus for JEE Chemistry. These objective practice sets help students evaluate their conceptual understanding and improve exam readiness.

Chapter-wise Objective Questions: Classification Of Elements and Periodicity In Properties

Access the complete set of multiple-choice questions for Classification Of Elements and Periodicity In Properties below. This focused format allows students to isolate specific topics for thorough review and uninterrupted practice alongside official JEE textbooks.

Multiple Choice Questions

Question 1: If the periodic table had contained 10 periods, the maximum number of elements in it would have been:
(a) 290
(b) 72
(c) 190
(d) 144
Show Answer & Explanation

Answer: (a) 290

Explanation:
1. Period lengths would be 2, 8, 8, 18, 18, 32, 32, 50, 50 and 72, which add up to 290.

Teacher's Note:
1. Each new period length follows the number of orbitals available: 2, 8, 18, 32, 50, 72.

Question 2: The elements with atomic numbers 102, 120, 107 and 82 belong respectively to the following blocks:
(a) f, s, d and p
(b) s, d, f and p
(c) d, f, s and p
(d) p, s, f and d
Show Answer & Explanation

Answer: (a) f, s, d and p

Explanation:
1. Z = 102 (No) is an actinoid (f-block); Z = 120 would be an alkaline earth (s-block); Z = 107 (Bh) is d-block and Z = 82 (Pb) is p-block.

Teacher's Note:
1. Identify the last subshell filled.

Question 3: The first ionisation energy of the first atom is greater than that of the second, whereas the reverse is true for their second ionisation energies. Which set is not in accordance with this?
(a) C, B
(b) B, Be
(c) P, S
(d) Mg, Na
Show Answer & Explanation

Answer: (b) B, Be

Explanation:
1. For B and Be, IE1 of B (801) < IE1 of Be (900), so the first condition fails. C/B, P/S and Mg/Na satisfy both conditions.

Teacher's Note:
1. Compare IE1 and IE2 for each pair.

Question 4: The correct order of ionic radii is:
(a) \( \ce{P^{3+}} \) > \( \ce{P^{5+}} \)
(b) \( \ce{Ti^{4+}} \) < \( \ce{Mn^{7+}} \)
(c) \( \ce{Cr^{6+}} \) > \( \ce{Cr^{3+}} \)
(d) \( \ce{K+} \) > \( \ce{Cl-} \)
Show Answer & Explanation

Answer: (a) \( \ce{P^{3+}} \) > \( \ce{P^{5+}} \)

Explanation:
1. Higher positive charge on the same element gives a smaller ion, so P\(^{3+}\) > P\(^{5+}\). In the others, Ti4+ (60 pm) > Mn7+ (46 pm), Cr3+ > Cr6+ and Cl- (181 pm) > K+ (138 pm).

Teacher's Note:
1. Same element: more positive charge, smaller radius.

Question 5: Lanthanoid contraction will not have any influence when we compare the sizes of:
(a) Y and La
(b) Zr and Hf
(c) Mo and W
(d) Tc and Re
Show Answer & Explanation

Answer: (a) Y and La

Explanation:
1. Both Zr/Hf, Mo/W and Tc/Re are 4d/5d pairs separated by the lanthanoids. Y and La are in group 3 before the lanthanoids start, so La is simply larger due to the extra shell.

Teacher's Note:
1. Contraction acts on elements after the 4f series.

Question 6: The p-block elements of the 6th period are represented as:
(a) [Xe] 5f\(^{14}\) 6d\(^{10}\) 6p\(^{1-6}\)
(b) [Rn] 5f\(^{14}\) 5d\(^{10}\) 6p\(^{1-6}\)
(c) [Xe] 4f\(^{14}\) 5d\(^{10}\) 6p\(^{1-6}\) (with 6s\(^2\))
(d) [Xe] 4f\(^{0}\) 5d\(^{10}\) 6p\(^{1-6}\)
Show Answer & Explanation

Answer: (c) [Xe] 4f\(^{14}\) 5d\(^{10}\) 6p\(^{1-6}\) (with 6s\(^2\))

Explanation:
1. In the 6th period after Hg the 4f and 5d subshells are full, and 6p fills from Tl to Rn with xenon core.

Teacher's Note:
1. The p-block of the 6th period begins after the 5d series.

Question 7: Which two of the following ions are closest to one another in size?
(a) \( \ce{Li+} \) and \( \ce{Na+} \)
(b) \( \ce{Be^{2+}} \) and \( \ce{Mg^{2+}} \)
(c) \( \ce{Li+} \) and \( \ce{Mg^{2+}} \)
(d) \( \ce{Be^{2+}} \) and \( \ce{Li+} \)
Show Answer & Explanation

Answer: (c) \( \ce{Li+} \) and \( \ce{Mg^{2+}} \)

Explanation:
1. Li\(^+\) (76 pm) and Mg\(^{2+}\) (72 pm) are diagonally related and similar in size.

Teacher's Note:
1. Diagonal relationship pairs have similar charge-to-radius ratios.

Question 8: The correct order of atomic size is:
(a) I > Li > F < Cl > Br
(b) I > Br > Cl > F > Li
(c) Li > I > F < Cl < Br
(d) Li > F < I < Br
Show Answer & Explanation

Answer: (c) Li > I > F < Cl < Br

Explanation:
1. Radii (pm): Li 152, I 133, F 64, Cl 99, Br 114; thus Li > I > F < Cl < Br.

Teacher's Note:
1. Use covalent radii for halogens.

Question 9: The incorrect order of ionisation potential is:
(a) Cu\(^+\) > Zn\(^+\)
(b) Tl < Al
(c) Cu < Zn
(d) Pd > Ag
Show Answer & Explanation

Answer: (b) Tl < Al

Explanation:
1. Tl (589) has higher IE1 than Al (577) because of poor shielding by 4f and 5d electrons, so Tl < Al is wrong.

Teacher's Note:
1. The lanthanoid contraction raises IE of Tl and Pb.

Question 10: Which of the following orders of electronegativity is correct?
(a) C > N
(b) C > Br
(c) Sr > Ca
(d) P > Si
Show Answer & Explanation

Answer: (d) P > Si

Explanation:
1. P (2.1) > Si (1.8) is correct; N (3.0) > C (2.5), Br (2.8) > C (2.5) and Ca (1.0) > Sr (0.95).

Teacher's Note:
1. Across a period EN increases.

Question 11: The correct order of electron affinity is:
(a) Cl > O > N > C
(b) Cl > N > C > O
(c) Cl > C > O > N
(d) Cl > O > C > N
Show Answer & Explanation

Answer: (d) Cl > O > C > N

Explanation:
1. EA (kJ per mol): Cl 349, O 141, C 122, N about zero.

Teacher's Note:
1. Nitrogen has an extremely low electron gain enthalpy.

Question 12: If the ionisation energies of Na, Mg and Si are 496, 737 and 786 kJ per mol respectively, the ionisation energy of Al (kJ per mol) is nearest to:
(a) 575
(b) 760
(c) 390
(d) 1120
Show Answer & Explanation

Answer: (a) 575

Explanation:
1. The order is Na (496) < Al < Mg (737) < Si (786). Al is lower than Mg because its 3p electron is easier to remove than a 3s\(^2\) electron, and the actual value is about 577 kJ per mol.

Teacher's Note:
1. Al and Ga show the dip in IE in group 13.

Question 13: Select the incorrect statement:
(a) Chloride ion is more electronegative than fluorine atom
(b) The size of \( \ce{H-} \) is larger than that of \( \ce{F-} \)
(c) Rb is more electropositive than Ca
(d) \( \ce{Na+} \) is more electronegative than Na
Show Answer & Explanation

Answer: (a) Chloride ion is more electronegative than fluorine atom

Explanation:
1. Cl\(^-\) is an anion and holds no tendency to attract further electrons; fluorine is the most electronegative element. The other three statements are correct.

Teacher's Note:
1. Cations are more electronegative than their atoms.

Question 14: The second ionisation energy is maximum for:
(a) Beryllium
(b) Magnesium
(c) Aluminium
(d) Boron
Show Answer & Explanation

Answer: (d) Boron

Explanation:
1. IE2 values (kJ per mol): B 2427, Be 1757, Al 1816, Mg 1451. Boron is the highest because B\(^+\) has a stable 2s\(^2\) configuration.

Teacher's Note:
1. Removal from a filled s subshell needs more energy.

Question 15: Which of the following ions has the lowest magnetic moment?
(a) \( \ce{Ni^{2+}} \)
(b) \( \ce{Co^{3+}} \)
(c) \( \ce{Fe^{2+}} \)
(d) \( \ce{Cu^{2+}} \)
Show Answer & Explanation

Answer: (d) \( \ce{Cu^{2+}} \)

Explanation:
1. Unpaired electrons: Cu2+ (3d9) 1, Ni2+ (3d8) 2, Co3+ (3d6) 4 and Fe2+ (3d6) 4 (high-spin). Cu2+ has the lowest moment (1.73 BM).

Teacher's Note:
1. Magnetic moment = root of n(n+2).

Question 16: The total number of d electrons present in an element with atomic number 78 is:
(a) 8
(b) 58
(c) 38
(d) 29
Show Answer & Explanation

Answer: (d) 29

Explanation:
1. Z = 78 is Pt: [Xe] 4f\(^{14}\) 5d\(^9\) 6s\(^1\). d electrons: 3d 10 + 4d 10 + 5d 9 = 29.

Teacher's Note:
1. Count d electrons of all shells, not just the valence one.

Question 17: In which of the following pairs is the radius of the second species greater than that of the first?
(a) Na, Mg
(b) Al, Be
(c) Li+, Be2+
(d) \( \ce{O^{2-}} \), \( \ce{N^{3-}} \)
Show Answer & Explanation

Answer: (d) \( \ce{O^{2-}} \), \( \ce{N^{3-}} \)

Explanation:
1. Both ions are isoelectronic (10 electrons). N\(^{3-}\) has fewer protons, so it is larger than O\(^{2-}\). In the other pairs the second species is smaller.

Teacher's Note:
1. Among isoelectronic species, lower nuclear charge means larger radius.

Question 18: The values of the second electron gain enthalpy of O and S respectively (kJ per mol) are:
(a) +580, +780
(b) +580, -780
(c) +780, +590
(d) -780, -580
Show Answer & Explanation

Answer: (c) +780, +590

Explanation:
1. O\(^-\) to O\(^{2-}\) has +780 kJ per mol (large repulsion in the small ion) and S\(^-\) to S\(^{2-}\) about +590 kJ per mol (the source value 580 is approximate).

Teacher's Note:
1. Second electron gain enthalpies are always positive.

Question 19: The highest electron affinity is observed in the configuration:
(a) 2s\(^2\)2p\(^4\)
(b) 2s\(^2\)2p\(^5\)
(c) 2s\(^2\)2p\(^3\)
(d) 2s\(^2\)2p\(^1\)
Show Answer & Explanation

Answer: (b) 2s\(^2\)2p\(^5\)

Explanation:
1. 2s\(^2\)2p\(^5\) is fluorine, which strongly gains one electron to reach neon configuration (-328 kJ per mol), more than O, N or B.

Teacher's Note:
1. Compare among elements of the same period.

Question 20: If an electron could have four spin quantum number values (the other quantum numbers remaining the same), which statement would be incorrect?
(a) Be would have been in the first period
(b) The fourth period would have contained 36 elements
(c) The number of periods would have been fewer than in the modern table
(d) The second period would have contained 12 elements
Show Answer & Explanation

Answer: (d) The second period would have contained 12 elements

Explanation:
1. Each orbital would hold 4 electrons.
2. First period: 1s holds 4, so Be (Z = 4) closes period 1. Second period: 2s and 2p = 4 orbitals, i.e. 16 elements (not 12). Fourth period: 4s, 3d and 4p = 9 orbitals, i.e. 36 elements.

Teacher's Note:
1. Count orbitals in each period and multiply by the electron capacity of an orbital.

Question 21: The incorrect order among the following is:
(a) IE\(_2\)(Mg) > IE\(_2\)(Na)
(b) IE\(_1\)(Al) < IE\(_1\)(Mg)
(c) IE\(_1\)(Na) < IE\(_1\)(Mg)
(d) IE\(_3\)(Mg) > IE\(_3\)(Al)
Show Answer & Explanation

Answer: (a) IE\(_2\)(Mg) > IE\(_2\)(Na)

Explanation:
1. IE2 of Na (4562) is far greater than IE2 of Mg (1451), so the given order is wrong.

Teacher's Note:
1. IE2 of an alkali metal is exceptionally large.

Question 22: Which of the following has the lowest first ionisation potential?
(a) Pb
(b) Sn
(c) Si
(d) C
Show Answer & Explanation

Answer: (b) Sn

Explanation:
1. IE1 (kJ per mol): Sn 709, Pb 716, Si 787 and C 1086. Sn is the lowest.

Teacher's Note:
1. In group 14, Pb has slightly higher IE than Sn.

Question 23: The total number of elements of the 5th period which have one or more 5d electrons is:
(a) zero
(b) 10
(c) 16
(d) 30
Show Answer & Explanation

Answer: (a) zero

Explanation:
1. In the 5th period the filling is 5s, 4d, 5p. The 5d subshell is not occupied in any ground state, so the answer is zero.

Teacher's Note:
1. The 5d subshell begins to fill only in the 6th period (La).

Question 24: Which statement is incorrect in relation to ionisation enthalpy?
(a) Ionisation enthalpy increases for each successive electron
(b) Removal of an electron from an orbital with a lower n value is easier than from an orbital with a higher n value
(c) The greatest increase is on removal of an electron from a core noble gas configuration
(d) End of valence electrons is marked by a big jump in ionisation enthalpy
Show Answer & Explanation

Answer: (b) Removal of an electron from an orbital with a lower n value is easier than from an orbital with a higher n value

Explanation:
1. Electrons in orbitals with lower n are closer to the nucleus and harder to remove, so the given statement is the reverse of the truth.

Teacher's Note:
1. Inner electrons are held tightly.

Classification Of Elements and Periodicity In Properties Objective Questions & Solutions for JEE Chemistry

JEE Chemistry Classification Of Elements and Periodicity In Properties Objective Test Questions

Review structured objective questions for JEE Chemistry Classification Of Elements and Periodicity In Properties. Built according to official JEE guidelines, these MCQ sets support daily revision and core concept reinforcement.

NCERT-Aligned Objective Questions and Solutions

Built using the official NCERT book for JEE, these Chemistry objective sets provide reliable academic guidance. Pair your practice with our recommended NCERT solutions to master optimal problem-solving approaches.

Next Steps in Your Exam Preparation

Explore our broader library of printable assignments, chapter notes, and mock tests designed to support continuous revision and secure higher marks in JEE assessments.

FAQs

Where can I access latest JEE Chemistry Classification Of Elements and Periodicity In Properties MCQs Set 26?

You can get most exhaustive JEE Chemistry Classification Of Elements and Periodicity In Properties MCQs Set 26 for free on StudiesToday.com. These MCQs for JEE Chemistry are updated for the 2026-27 academic session as per JEE examination standards.

Are Assertion-Reasoning and Case-Study MCQs included in the Chemistry JEE material?

Yes, our JEE Chemistry Classification Of Elements and Periodicity In Properties MCQs Set 26 include the latest type of questions, such as Assertion-Reasoning and Case-based MCQs. 50% of the JEE paper is now competency-based.

How do practicing Chemistry MCQs help in scoring full marks in JEE exams?

By solving our JEE Chemistry Classification Of Elements and Periodicity In Properties MCQs Set 26, JEE students can improve their accuracy and speed which is important as objective questions provide a chance to secure 100% marks in the Chemistry.

Do you provide answers and explanations for JEE Chemistry Classification Of Elements and Periodicity In Properties MCQs Set 26?

Yes, Chemistry MCQs for JEE have answer key and brief explanations to help students understand logic behind the correct option as its important for 2026 competency-focused JEE exams.

Can I practice these Chemistry JEE MCQs online?

Yes, you can also access online interactive tests for JEE Chemistry Classification Of Elements and Periodicity In Properties MCQs Set 26 on StudiesToday.com as they provide instant answers and score to help you track your progress in Chemistry.