Lesson 6.2: Chemistry (Basic Concepts, Atomic Structure, Reactions, Everyday Chemistry)
Chemistry is an important part of the General Science section for NDA and CDS exams. It helps aspirants understand matter, chemical reactions, and real-life applications relevant to defence and daily life.
1. Basic Concepts
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Matter: Solid, Liquid, Gas
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Atoms & Molecules: Structure, Atomic number, Mass number
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Elements, Compounds, Mixtures: Difference and examples
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States of Matter: Solid, Liquid, Gas, Plasma
2. Atomic Structure
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Electrons, Protons, Neutrons: Arrangement in shells
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Bohr Model: Energy levels and electron configuration
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Periodic Table: Groups, Periods, and Trends (Atomic radius, Ionization energy)
3. Chemical Reactions
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Types of Reactions:
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Combination, Decomposition, Displacement, Double displacement, Redox reactions
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Balancing Equations: Law of conservation of mass
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Acids, Bases, and Salts: Properties and uses
4. Everyday Chemistry
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Household Chemicals: Cleaning agents, detergents, soaps
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Environmental Chemistry: Pollution, Greenhouse effect, Water treatment
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Defence Applications: Explosives, propellants, fuel chemistry
Exam Tips
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Memorize common formulas and chemical equations
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Focus on periodic table trends and properties
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Solve previous year NDA & CDS chemistry questions
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Revise daily life examples to relate theory to practical applications
