In this class, we continue exploring the fundamental building blocks of matter—elements, mixtures, and compounds. Understanding these concepts is essential because they form the basis of all chemical reactions, materials, and processes encountered in everyday life as well as in defense technologies. For NDA/CDS aspirants, mastering these basics helps strengthen conceptual clarity, which is crucial for scoring well in the General Science section of the examination.
Subtopics Covered in Class
1. Elements – Revision & Deeper Understanding
- Recap of definition: Pure substances made of the same type of atoms
- Classification of elements: Metals, non-metals, metalloids
- Properties of metals vs. non-metals
- Symbols of common elements (as frequently asked in exams)
2. Compounds – Detailed Exploration
- Definition: Substances formed by chemical combination of elements
- Characteristics of compounds
- Fixed composition
- Cannot be separated by physical methods
- Formation involves chemical bonds
- Examples relevant for exams: Water, common salt, carbon dioxide, ammonia
- Difference between compounds and mixtures (focus on exam-oriented points)
3. Mixtures – Types & Characteristics
- Definition: Physical combination of two or more substances
- Properties of mixtures
- Variable composition
- Can be separated by physical methods
- Components retain individual properties
- Types of mixtures:
- Homogeneous (solutions)
- Heterogeneous (suspensions, colloids)
- Daily-life examples
4. Methods of Separation of Mixtures
(Important for NDA-level questions)
- Filtration
- Evaporation
- Distillation
- Magnetic separation
- Chromatography (brief introduction)
5. Difference Between Elements, Compounds & Mixtures
- Tabular comparison
- Frequently asked exam concepts
- Short tricks to remember differences
Relevance for NDA CDS 1 2026 Examination
- The General Science section includes 10–12 questions from basic Chemistry.
- Questions commonly asked:
- Properties of mixtures and compounds
- Separation methods
- Element symbols and characteristics
- This topic often appears in concept-based MCQs, so clear understanding rather than memorization is essential.
- Strengthening fundamental Chemistry helps improve overall accuracy in the GAT paper.
Conclusion
Elements, mixtures, and compounds form the foundation of Chemistry. A strong grasp of their definitions, properties, and differences prepares you not only for higher-level scientific concepts but also for scoring effectively in the NDA CDS 1 2026 Exam. With consistent practice and conceptual clarity, aspirants can handle this portion of the exam confidently and accurately.
