Classification of Elements and Periodicity in Properties NEET PYQs
Practice NEET previous year questions from Classification of Elements and Periodicity in Properties. These MCQs cover periodic trends, atomic size, ionisation energy, electron gain enthalpy, electronegativity, oxides and isoelectronic species with answers and clear explanations.
👉 Read theory:
Classification of Elements Chapter Notes
Q1. Which of the following oxides is most acidic in nature?
(NEET 2018)
- (A) Na2O
- (B) Al2O3
- (C) MgO
- (D) Cl2O7
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(D)
Show Explanation
Non-metal oxides with high oxidation state like Cl2O7 are strongly acidic.
Q2. The correct order of atomic radii in group 13 elements is:
(NEET 2018)
- (A) B > Al > Ga > In
- (B) B < Al > Ga < In
- (C) B < Al < Ga > In
- (D) B < Al < Ga < In
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(B)
Show Explanation
Due to d-block contraction, Ga has smaller radius than expected.
Q3. The element with atomic number 114 belongs to:
(NEET 2017)
- (A) Carbon family
- (B) Oxygen family
- (C) Nitrogen family
- (D) Halogen family
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(A)
Show Explanation
Element 114 (Flerovium) belongs to group 14 (carbon family).
Q4. Which order does NOT agree with the property indicated?
(NEET 2016)
- (A) I < Br < Cl (increasing electron gain enthalpy)
- (B) Li < Na < K (increasing metallic radius)
- (C) Al3+ < Mg2+ < Na+ < F− (increasing ionic size)
- (D) N < O < F (increasing first IE)
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(D)
Show Explanation
Oxygen has lower ionisation energy than nitrogen due to half-filled stability of nitrogen.
Q5. Ar, K+ and Ca2+ are isoelectronic. Increasing order of radii is:
(NEET 2015)
- (A) Ar < K+ < Ca2+
- (B) Ca2+ < K+ < Ar
- (C) K+ < Ar < Ca2+
- (D) Ca2+ < Ar < K+
Show Answer
(D)
Show Explanation
For isoelectronic species, radius decreases with increasing nuclear charge.
Q6. Which of the following orders of ionic radii is correct?
(NEET 2014)
- (A) H− > H > H+
- (B) Na+ > F− > O2−
- (C) F− > O2− > Na+
- (D) Al3+ > Mg2+ > N3−
Show Answer
(C)
Show Explanation
Among isoelectronic ions, greater negative charge → larger size.
Q7. Correct increasing order of first ionisation enthalpy for second period elements is:
(NEET 2019)
- (A) Li < Be < B < C < N < O < F < Ne
- (B) Li < B < Be < C < O < N < F < Ne
- (C) Li < Be < B < C < O < N < F < Ne
- (D) Li < B < Be < C < N < O < F < Ne
Show Answer
(B)
Show Explanation
B has lower IE than Be; O has lower IE than N due to pairing effect.
Q8. Which oxide is amphoteric?
(NEET 2019 Odisha)
- (A) Na2O
- (B) Al2O3
- (C) N2O
- (D) Cl2O7
Show Answer
(B)
Show Explanation
Aluminium oxide reacts with both acids and bases.
Q9. Zr and Hf have similar radii due to:
(NEET 2023)
- (A) Diagonal relationship
- (B) Lanthanoid contraction
- (C) Same period
- (D) Same atomic mass
Show Answer
(B)
Show Explanation
Poor shielding of f-electrons causes lanthanoid contraction.
Q10. Which element has maximum electron affinity?
(NEET 1999)
- (A) F
- (B) Cl
- (C) Br
- (D) I
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(B)
Show Explanation
Chlorine has highest EA due to optimum atomic size.
Q11. Metallic character in a period:
(NEET 1989)
- (A) Increases
- (B) Decreases
- (C) Remains constant
- (D) First increases then decreases
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(B)
Q12. Smallest ion among the following is:
(NEET 1996)
- (A) Na+
- (B) Mg2+
- (C) Al3+
- (D) O2−
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(C)
Q13. Atomic volume across a period:
(NEET 1993)
- (A) Increases
- (B) Decreases
- (C) Remains same
- (D) First decreases then increases
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(D)
Q14. Pauling electronegativity is useful in predicting:
(NEET 1989)
- (A) Bond polarity
- (B) Atomic mass
- (C) Coordination number
- (D) Crystal structure
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(A)
Q15. Proton has very high:
(NEET 1993)
- (A) Radius
- (B) Hydration energy
- (C) Ionisation energy
- (D) Atomic volume
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(B)
👉 More Classification of Elements & Periodicity NEET PYQs will be added gradually.