The NDA (National Defence Academy) & CDS (Combined Defence Services) exams are prestigious national-level examinations conducted for candidates who wish to join the Indian Armed Forces—Army, Navy, and Air Force.

For students starting early (Class 6 and above), building a strong foundation in Science, Maths, and General Knowledge is extremely helpful. Learning topics like the Mole Concept and Atomic Structure early strengthens scientific thinking that becomes beneficial in later competitive exams including NDA CDS.

Topic 1: Mole Concept – Overview

Although the Mole Concept is usually taught in higher classes, at Class 6 level we introduce only the basic idea:
A mole is a way of counting particles like atoms and molecules—similar to how “dozen” means 12 items.

Subtopics (Class 6 Level – Simplified)

1. What is a Mole?
   • A special number used to count atoms/molecules.
   • Like dozen = 12, mole = very large number (not memorized at this level).
2. Why Do We Need a Mole?
   • Atoms are extremely tiny, so we count them using the mole idea.
3. Simple Examples
   • Counting objects using groups (dozen, pair, score, and mole concept analogy).
4. MCQ Style Learning
   • Identifying which idea describes a mole.
   • Simple comparison questions (dozen : 12 :: mole : ___ ).

Short Summary (for conclusion)

The mole helps scientists count extremely small particles easily, just like we use “dozen.” It forms the base for chemistry calculations in higher classes and for exams like NDA CDS later.

Topic 2: Atomic Structure – Overview

Atoms are the building blocks of everything around us. Understanding their structure is the first step toward understanding molecules, reactions, and matter.

Subtopics (Class 6 Level – Simplified)

1. What is an Atom?
   • Smallest unit of matter that cannot be seen with naked eyes.
2. Parts of an Atom
   • Protons – positively charged
   • Neutrons – neutral (no charge)
   • Electrons – negatively charged
3. Nucleus and Electron Shells
   • Protons and neutrons stay in the nucleus (center).
   • Electrons revolve around the nucleus in shells.
4. Examples
   • Hydrogen atom (simplest with 1 proton, 1 electron).
   • Use of models or diagrams for understanding.
5. MCQ Style Learning
   • Identifying proton/electron charges
   • Choosing which part of the atom is in the nucleus
   • Small conceptual questions

Short Summary (for conclusion)

Atoms are tiny particles made of protons, neutrons, and electrons. Knowing how an atom is built helps us understand all chemical reactions and prepares us for advanced concepts relevant for exams like NDA CDS in future.

Conclusion

The Mole Concept and Atomic Structure form the very foundation of chemistry. At Class 6 level, understanding them through simple explanations and MCQs helps build scientific reasoning. These fundamental ideas grow into more advanced topics that appear in higher classes and competitive exams like NDA CDS 1 2026, giving students an early advantage.