Atomic Structure and Periodic Classification
35 NDA Chemistry previous year questions (PYQs) from 16 papers, 2017 to 2026, with answers and worked solutions.
About this chapter
- Difficulty: 18 easy · 14 moderate · 3 hard.
- Most-asked subtopics: Periodic Trends, Valency and Atomicity (12), Atomic Number, Mass Number and Subatomic Particles (7), Atomic Models: Dalton, Rutherford, Bohr (6).
- Updated 18 May 2026.
#1Atomic Models: Dalton, Rutherford, Bohr
#2Atomic Models: Dalton, Rutherford, Bohr
- NDA · Apr 2021 · Q86Moderate
#3Atomic Models: Dalton, Rutherford, Bohr
#4Atomic Models: Dalton, Rutherford, Bohr
#5Atomic Models: Dalton, Rutherford, Bohr
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- NDA · Apr 2025 · Q74Moderate
#6Atomic Models: Dalton, Rutherford, Bohr
#7Atomic Number, Mass Number and Subatomic Particles
- NDA · Sep 2018 · Q63Moderate
#8Atomic Number, Mass Number and Subatomic Particles
#9Atomic Number, Mass Number and Subatomic Particles
#10Atomic Number, Mass Number and Subatomic Particles
#11Atomic Number, Mass Number and Subatomic Particles
#12Atomic Number, Mass Number and Subatomic Particles
- NDA · Apr 2025 · Q72Moderate
#13Atomic Number, Mass Number and Subatomic Particles
- NDA · Apr 2020 · Q97Moderate
#14Isotopes and Isoelectronic Species
- NDA · Sep 2017 · Q83Moderate
#15Isotopes and Isoelectronic Species
#16Isotopes and Isoelectronic Species
#17Isotopes and Isoelectronic Species
- NDA · Sep 2021 · Q142Moderate
#18Isotopes and Isoelectronic Species
- NDA · Apr 2024 · Q64Moderate
#19Isotopes and Isoelectronic Species
#20Electron Configuration and Valence Shells
#21Electron Configuration and Valence Shells
- NDA · Apr 2022 · Q84Moderate
#22Electron Configuration and Valence Shells
#23Electron Configuration and Valence Shells
#24Periodic Trends, Valency and Atomicity
#25Periodic Trends, Valency and Atomicity
#26Periodic Trends, Valency and Atomicity
- NDA · Apr 2017 · Q94Moderate
#27Periodic Trends, Valency and Atomicity
#28Periodic Trends, Valency and Atomicity
#29Periodic Trends, Valency and Atomicity
#30Periodic Trends, Valency and Atomicity
#31Periodic Trends, Valency and Atomicity
- NDA · Apr 2023 · Q112Moderate
#32Periodic Trends, Valency and Atomicity
- NDA · Sep 2024 · Q58Moderate
#33Periodic Trends, Valency and Atomicity
- NDA · Sep 2025 · Q103Moderate
#34Periodic Trends, Valency and Atomicity
- NDA · Apr 2025 · Q75Moderate
#35Periodic Trends, Valency and Atomicity